[FFmpeg-devel,v9,1/2] libavformat: add dvdvideo demuxer, powered by libdvdnav and libdvdread

Thank you to all the reviewers for your time.

[Remaining Questions]

Andreas R:
> This makes this code add an AVStream to the child AVFormatContext. This
> is not how it is supposed to be. You may not add AVStreams behind an
> input AVFormatContext's back.
The intent here is that I need to tell the subdemuxer which streams to expect,
hence why I don't call find_stream_info() on it or let it probe on it's own.
The DVD IFO headers give me all of the information in advance.
This is required AFAIK because there might be forced subtitle tracks that do not
start until mid-playback. After further discussion with reviewer,
it appears the concern is more about long term maintainability:
> Some (de)muxers (i.e. the avi demuxer) use AVStream.priv_data to store some per-stream data.
> They allocate this immediately after having added the stream.
> Imagine someone changing the mpegps demuxer in this way.
> Then it would crash when it tried to access the stream's private data
> in case the stream has been added by an outside demuxer."
I respect this feedback, makes sense. I'm not sure if this is a show stopper or not
but thought to take the community's overall opinion on a solution (if any)?

> Given that this code here is absolutely not speed relevant, the LUT
> can be avoided by using av_clip_uint8(value - 1024). [Andreas R.]
I had a hard time trying to make this work with YUV_TO_RGB2_CCIR() which 
seems to expect the LUT. Happy to remove it if possible, just a little stuck on this.
Thank you.

[Addressed]

- Documentation fixes
- Robust logging messages (also printing explicit error reason from dvdnav)
- Structure fixes (using const, etc.)
- Condensed libdvdnav/libdvdread logging callbacks
- Moved some variables to the stack (and removed unchecked allocations, tired eyes, thx)
- Formatting compliance (best effort, please let me know if further needed - thx)

[Addressed, with response]

Stefano S:
> unrelated, but it might be useful to have a -list-titles option
Agreed :-) This feature is still a work in progress as it is not a straightforward job
and there are good alternative tools, so I had to deprioritize (currently in tinkering phase).
Hopefully this is fair, thanks.

Andreas R:
> What is this header used for?
avcodec.c - used to access avctx and set FF_CODEC_PROPERTY_CLOSED_CAPTIONS
Intent was to declare availability of EIA608 CC, as this is known at the container level.

url.h - used for ff_check_interrupt() - This is in my assumption to ensure a
safe cancellation path while using the "preindex" option, which requires
a full read of the disc to determine correct chapter markers.

>  Why not? We have AV_DISPOSITION_KARAOKE.
Thanks - added the disposition and also cleared up the point of the message,
which is to say that karaoke tracks have additional extension metadata
located in the IFO headers. I have not studied how to parse it at this time.

Signed-off-by: Marth64 <marth64@proxyid.net>
---
 Changelog                 |    2 +
 configure                 |    8 +
 doc/demuxers.texi         |  130 ++++
 libavformat/Makefile      |    1 +
 libavformat/allformats.c  |    1 +
 libavformat/dvdvideodec.c | 1419 +++++++++++++++++++++++++++++++++++++
 6 files changed, 1561 insertions(+)
 create mode 100644 libavformat/dvdvideodec.c

Please ignore, see v10.

On Fri, Feb 9, 2024 at 1:17 AM Marth64 <marth64@proxyid.net> wrote:

> Thank you to all the reviewers for your time.
>
> [Remaining Questions]
>
> Andreas R:
> > This makes this code add an AVStream to the child AVFormatContext. This
> > is not how it is supposed to be. You may not add AVStreams behind an
> > input AVFormatContext's back.
> The intent here is that I need to tell the subdemuxer which streams to
> expect,
> hence why I don't call find_stream_info() on it or let it probe on it's
> own.
> The DVD IFO headers give me all of the information in advance.
> This is required AFAIK because there might be forced subtitle tracks that
> do not
> start until mid-playback. After further discussion with reviewer,
> it appears the concern is more about long term maintainability:
> > Some (de)muxers (i.e. the avi demuxer) use AVStream.priv_data to store
> some per-stream data.
> > They allocate this immediately after having added the stream.
> > Imagine someone changing the mpegps demuxer in this way.
> > Then it would crash when it tried to access the stream's private data
> > in case the stream has been added by an outside demuxer."
> I respect this feedback, makes sense. I'm not sure if this is a show
> stopper or not
> but thought to take the community's overall opinion on a solution (if any)?
>
> > Given that this code here is absolutely not speed relevant, the LUT
> > can be avoided by using av_clip_uint8(value - 1024). [Andreas R.]
> I had a hard time trying to make this work with YUV_TO_RGB2_CCIR() which
> seems to expect the LUT. Happy to remove it if possible, just a little
> stuck on this.
> Thank you.
>
> [Addressed]
>
> - Documentation fixes
> - Robust logging messages (also printing explicit error reason from dvdnav)
> - Structure fixes (using const, etc.)
> - Condensed libdvdnav/libdvdread logging callbacks
> - Moved some variables to the stack (and removed unchecked allocations,
> tired eyes, thx)
> - Formatting compliance (best effort, please let me know if further needed
> - thx)
>
> [Addressed, with response]
>
> Stefano S:
> > unrelated, but it might be useful to have a -list-titles option
> Agreed :-) This feature is still a work in progress as it is not a
> straightforward job
> and there are good alternative tools, so I had to deprioritize (currently
> in tinkering phase).
> Hopefully this is fair, thanks.
>
> Andreas R:
> > What is this header used for?
> avcodec.c - used to access avctx and set FF_CODEC_PROPERTY_CLOSED_CAPTIONS
> Intent was to declare availability of EIA608 CC, as this is known at the
> container level.
>
> url.h - used for ff_check_interrupt() - This is in my assumption to ensure
> a
> safe cancellation path while using the "preindex" option, which requires
> a full read of the disc to determine correct chapter markers.
>
> >  Why not? We have AV_DISPOSITION_KARAOKE.
> Thanks - added the disposition and also cleared up the point of the
> message,
> which is to say that karaoke tracks have additional extension metadata
> located in the IFO headers. I have not studied how to parse it at this
> time.
>
> Signed-off-by: Marth64 <marth64@proxyid.net>
> ---
>  Changelog                 |    2 +
>  configure                 |    8 +
>  doc/demuxers.texi         |  130 ++++
>  libavformat/Makefile      |    1 +
>  libavformat/allformats.c  |    1 +
>  libavformat/dvdvideodec.c | 1419 +++++++++++++++++++++++++++++++++++++
>  6 files changed, 1561 insertions(+)
>  create mode 100644 libavformat/dvdvideodec.c
>
> diff --git a/Changelog b/Changelog
> index c5fb21d198..88653bc6d3 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -24,6 +24,8 @@ version <next>:
>  - ffmpeg CLI options may now be used as -/opt <path>, which is equivalent
>    to -opt <contents of file <path>>
>  - showinfo bitstream filter
> +- DVD-Video demuxer, powered by libdvdnav and libdvdread
> +
>
>  version 6.1:
>  - libaribcaption decoder
> diff --git a/configure b/configure
> index f72533b7d2..831b9f6cb6 100755
> --- a/configure
> +++ b/configure
> @@ -227,6 +227,8 @@ External library support:
>    --enable-libdavs2        enable AVS2 decoding via libdavs2 [no]
>    --enable-libdc1394       enable IIDC-1394 grabbing using libdc1394
>                             and libraw1394 [no]
> +  --enable-libdvdnav       enable libdvdnav, needed for DVD demuxing [no]
> +  --enable-libdvdread      enable libdvdread, needed for DVD demuxing [no]
>    --enable-libfdk-aac      enable AAC de/encoding via libfdk-aac [no]
>    --enable-libflite        enable flite (voice synthesis) support via
> libflite [no]
>    --enable-libfontconfig   enable libfontconfig, useful for drawtext
> filter [no]
> @@ -1806,6 +1808,8 @@ EXTERNAL_LIBRARY_GPL_LIST="
>      frei0r
>      libcdio
>      libdavs2
> +    libdvdnav
> +    libdvdread
>      librubberband
>      libvidstab
>      libx264
> @@ -3523,6 +3527,8 @@ dts_demuxer_select="dca_parser"
>  dtshd_demuxer_select="dca_parser"
>  dv_demuxer_select="dvprofile"
>  dv_muxer_select="dvprofile"
> +dvdvideo_demuxer_select="mpegps_demuxer"
> +dvdvideo_demuxer_deps="libdvdnav libdvdread"
>  dxa_demuxer_select="riffdec"
>  eac3_demuxer_select="ac3_parser"
>  evc_demuxer_select="evc_frame_merge_bsf evc_parser"
> @@ -6771,6 +6777,8 @@ enabled libdav1d          && require_pkg_config
> libdav1d "dav1d >= 0.5.0" "dav1d
>  enabled libdavs2          && require_pkg_config libdavs2 "davs2 >= 1.6.0"
> davs2.h davs2_decoder_open
>  enabled libdc1394         && require_pkg_config libdc1394 libdc1394-2
> dc1394/dc1394.h dc1394_new
>  enabled libdrm            && check_pkg_config libdrm libdrm xf86drm.h
> drmGetVersion
> +enabled libdvdnav         && require_pkg_config libdvdnav "dvdnav >=
> 6.1.1" dvdnav/dvdnav.h dvdnav_open2
> +enabled libdvdread        && require_pkg_config libdvdread "dvdread >=
> 6.1.2" dvdread/dvd_reader.h DVDOpen2 -ldvdread
>  enabled libfdk_aac        && { check_pkg_config libfdk_aac fdk-aac
> "fdk-aac/aacenc_lib.h" aacEncOpen ||
>                                 { require libfdk_aac fdk-aac/aacenc_lib.h
> aacEncOpen -lfdk-aac &&
>                                   warn "using libfdk without pkg-config";
> } }
> diff --git a/doc/demuxers.texi b/doc/demuxers.texi
> index e4c5b560a6..062ea2ea42 100644
> --- a/doc/demuxers.texi
> +++ b/doc/demuxers.texi
> @@ -285,6 +285,136 @@ This demuxer accepts the following option:
>
>  @end table
>
> +@section dvdvideo
> +
> +DVD-Video demuxer, powered by libdvdnav and libdvdread.
> +
> +Can directly ingest DVD titles, specifically sequential PGCs,
> +into a conversion pipeline. Menus and seeking are not supported at this
> time.
> +
> +Block devices (DVD drives), ISO files, and directory structures are
> accepted.
> +Activate with @code{-f dvdvideo} in front of one of these inputs.
> +
> +Underlying playback is handled by libdvdnav, and structure parsing by
> libdvdread.
> +FFmpeg must be built with GPL library support available as well as the
> +configure switches @code{--enable-libdvdnav} and
> @code{--enable-libdvdread}.
> +
> +You will need to provide either the desired "title number" or exact
> PGC/PG coordinates.
> +Many open-source DVD players and tools can aid in providing this
> information.
> +If not specified, the demuxer will default to title 1 which works for
> many discs.
> +However, due to the flexibility of the format, it is recommended to check
> manually.
> +There are many discs that are authored strangely or with invalid headers.
> +
> +If the input is a real DVD drive, please note that there are some drives
> which may
> +silently fail on reading bad sectors from the disc, returning random bits
> instead
> +which is effectively corrupt data. This is especially prominent on aging
> or rotting discs.
> +A second pass and integrity checks would be needed to detect the
> corruption.
> +This is not an FFmpeg issue.
> +
> +@subsection Background
> +
> +DVD-Video is not a directly accessible, linear container format in the
> +traditional sense. Instead, it allows for complex and programmatic
> playback of
> +carefully muxed MPEG-PS streams that are stored in headerless VOB files.
> +To the end-user, these streams are known simply as "titles", but the
> actual
> +logical playback sequence is defined by one or more "PGCs", or Program
> Group Chains,
> +within the title. The PGC is in turn comprised of multiple "PGs", or
> Programs",
> +which are the actual video segments (and for a typical video feature,
> sequentially
> +ordered). The PGC structure, along with stream layout and metadata, are
> stored in
> +IFO files that need to be parsed. PGCs can be thought of as playlists in
> easier terms.
> +
> +An actual DVD player relies on user GUI interaction via menus and an
> internal VM
> +to drive the direction of demuxing. Generally, the user would either
> navigate (via menus)
> +or automatically be redirected to the PGC of their choice. During this
> process and
> +the subsequent playback, the DVD player's internal VM also maintains a
> state and
> +executes instructions that can create jumps to different sectors during
> playback.
> +This is why libdvdnav is involved, as a linear read of the MPEG-PS blobs
> on the
> +disc (VOBs) is not enough to produce the right sequence in many cases.
> +
> +There are many other DVD structures (a long subject) that will not be
> discussed here.
> +NAV packets, in particular, are handled by this demuxer to build accurate
> timing
> +but not emitted as a stream. For a good high-level understanding, refer
> to:
> +@url{
> https://code.videolan.org/videolan/libdvdnav/-/blob/master/doc/dvd_structures
> }
> +
> +@subsection Options
> +
> +This demuxer accepts the following options:
> +
> +@table @option
> +
> +@item title @var{int}
> +The title number to play. Must be set if @option{pgc} and @option{pg} are
> not set.
> +Default is 0 (auto), which currently only selects the first available
> title (title 1)
> +and notifies the user about the implications.
> +
> +@item chapter_start @var{int}
> +The chapter, or PTT (part-of-title), number to start at. Default is 1.
> +
> +@item chapter_end @var{int}
> +The chapter, or PTT (part-of-title), number to end at. Default is 0,
> +which is a special value to signal end at the last possible chapter.
> +
> +@item angle @var{int}
> +The video angle number, referring to what is essentially an additional
> +video stream that is composed from alternate frames interleaved in the
> VOBs.
> +Default is 1.
> +
> +@item region @var{int}
> +The region code to use for playback. Some discs may use this to default
> playback
> +at a particular angle in different regions. This option will not affect
> the region code
> +of a real DVD drive, if used as an input. Default is 0, "world".
> +
> +@item pgc @var{int}
> +The entry PGC to start playback, in conjunction with @option{pg}.
> +Alternative to setting @option{title}.
> +Chapter markers are not supported at this time.
> +Default is 0, automatically resolve from value of @option{title}.
> +
> +@item pg @var{int}
> +The entry PG to start playback, in conjunction with @option{pgc}.
> +Alternative to setting @option{title}.
> +Chapter markers are not supported at this time.
> +Default is 0, automatically resolve from value of @option{title}.
> +
> +@item preindex @var{bool}
> +Enable this to have accurate chapter (PTT) markers and duration
> measurement,
> +which requires a slow second pass read in order to index the chapter
> marker
> +timestamps from NAV packets. This is non-ideal extra work for real
> optical drives.
> +It is recommended and faster to use this option with a backup of the DVD
> structure
> +stored on a hard drive. Not compatible with @option{pgc} and @option{pg}.
> +Default is 0, false.
> +
> +@item trim @var{bool}
> +Skip padding cells (i.e. cells shorter than 1 second) from the beginning.
> +There exist many discs with filler segments at the beginning of the PGC,
> +often with junk data intended for controlling a real DVD player's
> +buffering speed and with no other material data value.
> +Default is 1, true.
> +
> +@end table
> +
> +@subsection Examples
> +
> +@itemize
> +@item
> +Open title 3 from a given DVD structure:
> +@example
> +ffmpeg -f dvdvideo -title 3 -i <path to DVD> ...
> +@end example
> +
> +@item
> +Open chapters 3-6 from title 1 from a given DVD structure:
> +@example
> +ffmpeg -f dvdvideo -chapter_start 3 -chapter_end 6 -title 1 -i <path to
> DVD> ...
> +@end example
> +
> +@item
> +Open only chapter 5 from title 1 from a given DVD structure:
> +@example
> +ffmpeg -f dvdvideo -chapter_start 5 -chapter_end 5 -title 1 -i <path to
> DVD> ...
> +@end example
> +@end itemize
> +
>  @section ea
>
>  Electronic Arts Multimedia format demuxer.
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index 05b9b8a115..df69734877 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -192,6 +192,7 @@ OBJS-$(CONFIG_DTS_MUXER)                 += rawenc.o
>  OBJS-$(CONFIG_DV_MUXER)                  += dvenc.o
>  OBJS-$(CONFIG_DVBSUB_DEMUXER)            += dvbsub.o rawdec.o
>  OBJS-$(CONFIG_DVBTXT_DEMUXER)            += dvbtxt.o rawdec.o
> +OBJS-$(CONFIG_DVDVIDEO_DEMUXER)          += dvdvideodec.o
>  OBJS-$(CONFIG_DXA_DEMUXER)               += dxa.o
>  OBJS-$(CONFIG_EA_CDATA_DEMUXER)          += eacdata.o
>  OBJS-$(CONFIG_EA_DEMUXER)                += electronicarts.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index b04b43cab3..3e905c23f8 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -150,6 +150,7 @@ extern const AVInputFormat  ff_dv_demuxer;
>  extern const FFOutputFormat ff_dv_muxer;
>  extern const AVInputFormat  ff_dvbsub_demuxer;
>  extern const AVInputFormat  ff_dvbtxt_demuxer;
> +extern const AVInputFormat  ff_dvdvideo_demuxer;
>  extern const AVInputFormat  ff_dxa_demuxer;
>  extern const AVInputFormat  ff_ea_demuxer;
>  extern const AVInputFormat  ff_ea_cdata_demuxer;
> diff --git a/libavformat/dvdvideodec.c b/libavformat/dvdvideodec.c
> new file mode 100644
> index 0000000000..c8628609c9
> --- /dev/null
> +++ b/libavformat/dvdvideodec.c
> @@ -0,0 +1,1419 @@
> +/*
> + * DVD-Video demuxer, powered by libdvdnav and libdvdread
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> 02110-1301 USA
> + */
> +
> +/*
> + * See doc/demuxers.texi for a high-level overview.
> + *
> + * The tactical approach is as follows:
> + * 1) Open the volume with dvdread
> + * 2) Analyze the user-requested title and PGC coordinates in the IFO
> structures
> + * 3) Request playback at the coordinates and chosen angle with dvdnav
> + * 5) Begin the playback (reading and demuxing) of MPEG-PS blocks
> + * 6) End playback if navigation goes backwards, to a menu, or a
> different PGC or angle
> + * 7) Close the dvdnav VM, and free dvdread's IFO structures
> + */
> +
> +#include <dvdnav/dvdnav.h>
> +#include <dvdread/dvd_reader.h>
> +#include <dvdread/ifo_read.h>
> +#include <dvdread/ifo_types.h>
> +#include <dvdread/nav_read.h>
> +
> +#include "libavcodec/avcodec.h"
> +#include "libavutil/avstring.h"
> +#include "libavutil/avutil.h"
> +#include "libavutil/intreadwrite.h"
> +#include "libavutil/mem.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/samplefmt.h"
> +#include "libavutil/time.h"
> +#include "libavutil/timestamp.h"
> +
> +#include "avformat.h"
> +#include "avio_internal.h"
> +#include "avlanguage.h"
> +#include "demux.h"
> +#include "internal.h"
> +#include "url.h"
> +
> +#define DVDVIDEO_MAX_PS_SEARCH_BLOCKS                   128
> +#define DVDVIDEO_BLOCK_SIZE                             2048
> +#define DVDVIDEO_TIME_BASE_Q                            (AVRational) { 1,
> 90000 }
> +#define DVDVIDEO_PTS_WRAP_BITS                          64 /* VOBUs use
> 32 (PES allows 33) */
> +
> +#define DVDVIDEO_LIBDVDX_LOG_BUFFER_SIZE                1024
> +
> +enum DVDVideoSubpictureViewport {
> +    DVDVIDEO_SUBP_VIEWPORT_FULLSCREEN,
> +    DVDVIDEO_SUBP_VIEWPORT_WIDESCREEN,
> +    DVDVIDEO_SUBP_VIEWPORT_LETTERBOX,
> +    DVDVIDEO_SUBP_VIEWPORT_PANSCAN
> +};
> +static const char dvdvideo_subp_viewport_labels[4][13] = {
> +    "Fullscreen", "Widescreen", "Letterbox", "Pan and Scan"
> +};
> +
> +typedef struct DVDVideoVTSVideoStreamEntry {
> +    int                                 startcode;
> +    enum AVCodecID                      codec_id;
> +    int                                 width;
> +    int                                 height;
> +    AVRational                          dar;
> +    AVRational                          framerate;
> +    int                                 has_cc;
> +} DVDVideoVTSVideoStreamEntry;
> +
> +typedef struct DVDVideoPGCAudioStreamEntry {
> +    int                                 startcode;
> +    enum AVCodecID                      codec_id;
> +    int                                 sample_fmt;
> +    int                                 sample_rate;
> +    int                                 bit_depth;
> +    int                                 nb_channels;
> +    AVChannelLayout                     ch_layout;
> +    int                                 disposition;
> +    const char                          *lang_iso;
> +} DVDVideoPGCAudioStreamEntry;
> +
> +typedef struct DVDVideoPGCSubtitleStreamEntry {
> +    int                                 startcode;
> +    enum DVDVideoSubpictureViewport     viewport;
> +    int                                 disposition;
> +    const char                          *lang_iso;
> +} DVDVideoPGCSubtitleStreamEntry;
> +
> +typedef struct DVDVideoPlaybackState {
> +    int                         celln;              /* ID of the active
> cell */
> +    int                         entry_pgn;          /* ID of the PG we
> are starting in */
> +    int                         in_pgc;             /* if our navigator
> is in the PGC */
> +    int                         in_ps;              /* if our navigator
> is in the program stream */
> +    int                         in_vts;             /* if our navigator
> is in the VTS */
> +    int64_t                     nav_pts;            /* PTS according to
> IFO, not frame-accurate */
> +    int                         nb_cells_played;    /* number of cells
> played back so far */
> +    uint64_t                    pgc_duration_est;   /* estimated duration
> as reported by IFO */
> +    uint64_t                    pgc_elapsed;        /* the elapsed time
> of the PGC, cell-relative */
> +    int                         pgc_nb_pg_est;      /* number of PGs as
> reported by IFOs */
> +    int                         pgcn;               /* ID of the PGC we
> are playing */
> +    int                         pgn;                /* ID of the PG we
> are in now */
> +    int                         ptt;                /* ID of the chapter
> we are in now */
> +    int64_t                     ts_offset;          /* PTS discontinuity
> offset (ex. VOB change) */
> +    uint32_t                    vobu_duration;      /* duration of the
> current VOBU */
> +    uint32_t                    vobu_e_ptm;         /* end PTS of the
> current VOBU */
> +    int                         vtsn;               /* ID of the active
> VTS (video title set) */
> +    uint64_t                    *pgc_pg_times_est;  /* PG start times as
> reported by IFO */
> +    pgc_t                       *pgc;               /* handle to the
> active PGC */
> +    dvdnav_t                    *dvdnav;            /* handle to
> libdvdnav */
> +} DVDVideoPlaybackState;
> +
> +typedef struct DVDVideoDemuxContext {
> +    const AVClass               *class;
> +
> +    /* options */
> +    int                         opt_angle;          /* the user-provided
> angle number (1-indexed) */
> +    int                         opt_chapter_end;    /* the user-provided
> exit PTT (0 for last) */
> +    int                         opt_chapter_start;  /* the user-provided
> entry PTT (1-indexed) */
> +    int                         opt_pg;             /* the user-provided
> PG number (1-indexed) */
> +    int                         opt_pgc;            /* the user-provided
> PGC number (1-indexed) */
> +    int                         opt_preindex;       /* pre-indexing mode
> (2-pass read) */
> +    int                         opt_region;         /* the user-provided
> region digit */
> +    int                         opt_title;          /* the user-provided
> title number (1-indexed) */
> +    int                         opt_trim;           /* trim padding cells
> at beginning */
> +
> +    /* subdemux */
> +    const AVInputFormat         *mpeg_fmt;          /* inner MPEG-PS
> (VOB) demuxer */
> +    AVFormatContext             *mpeg_ctx;          /* context for inner
> demuxer */
> +    uint8_t                     *mpeg_buf;          /* buffer for inner
> demuxer */
> +    FFIOContext                 mpeg_pb;            /* buffer context for
> inner demuxer */
> +
> +    /* volume */
> +    dvd_reader_t                *dvdread;           /* handle to
> libdvdread */
> +    ifo_handle_t                *vmg_ifo;           /* handle to the VMG
> (VIDEO_TS.IFO) */
> +    ifo_handle_t                *vts_ifo;           /* handle to the
> active VTS (VTS_nn_n.IFO) */
> +
> +    /* playback control */
> +    int64_t                     first_pts;          /* the starting PTS
> offset of the PGC */
> +    uint64_t                    duration_ptm;       /* total duration in
> DVD MPEG timebase */
> +    int                         play_end;           /* signal EOF to the
> parent demuxer */
> +    DVDVideoPlaybackState       play_state;         /* the active
> playback state */
> +    int                         play_started;       /* signal that
> playback has started */
> +    int                         segment_started;    /* signal that
> subdemuxer is on a segment */
> +} DVDVideoDemuxContext;
> +
> +static void dvdvideo_libdvdread_log(void *opaque, dvd_logger_level_t
> level,
> +                                    const char *msg, va_list msg_va)
> +{
> +    AVFormatContext *s = opaque;
> +    char msg_buf[DVDVIDEO_LIBDVDX_LOG_BUFFER_SIZE];
> +    int lavu_level = AV_LOG_DEBUG;
> +
> +    vsnprintf(msg_buf, sizeof(msg_buf), msg, msg_va);
> +
> +    if (level == DVD_LOGGER_LEVEL_ERROR)
> +        lavu_level = AV_LOG_ERROR;
> +    else if (level == DVD_LOGGER_LEVEL_WARN)
> +        lavu_level = AV_LOG_WARNING;
> +
> +    av_log(s, lavu_level, "libdvdread: %s\n", msg_buf);
> +}
> +
> +static void dvdvideo_libdvdnav_log(void *opaque, dvdnav_logger_level_t
> level,
> +                                   const char *msg, va_list msg_va)
> +{
> +    AVFormatContext *s = opaque;
> +    char msg_buf[DVDVIDEO_LIBDVDX_LOG_BUFFER_SIZE];
> +    int lavu_level = AV_LOG_DEBUG;
> +
> +    vsnprintf(msg_buf, sizeof(msg_buf), msg, msg_va);
> +
> +    if (level == DVDNAV_LOGGER_LEVEL_ERROR)
> +        lavu_level = AV_LOG_ERROR;
> +    /* some discs have invalid language codes set for menus, which throws
> noisy warnings */
> +    else if (level == DVDNAV_LOGGER_LEVEL_WARN && !av_strstart(msg,
> "Language", NULL))
> +        lavu_level = AV_LOG_WARNING;
> +
> +    av_log(s, lavu_level, "libdvdnav: %s\n", msg_buf);
> +}
> +
> +static void dvdvideo_ifo_close(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    if (c->vts_ifo)
> +        ifoClose(c->vts_ifo);
> +
> +    if (c->vmg_ifo)
> +        ifoClose(c->vmg_ifo);
> +
> +    if (c->dvdread)
> +        DVDClose(c->dvdread);
> +}
> +
> +static int dvdvideo_ifo_open(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    dvd_logger_cb dvdread_log_cb;
> +    title_info_t title_info;
> +
> +    dvdread_log_cb = (dvd_logger_cb) { .pf_log = dvdvideo_libdvdread_log
> };
> +    c->dvdread = DVDOpen2(s, &dvdread_log_cb, s->url);
> +
> +    if (!c->dvdread) {
> +        av_log(s, AV_LOG_ERROR, "Unable to open the DVD-Video
> structure\n");
> +
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    if (!(c->vmg_ifo = ifoOpen(c->dvdread, 0))) {
> +        av_log(s, AV_LOG_ERROR, "Unable to open the VMG
> (VIDEO_TS.IFO)\n");
> +
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    if (c->opt_title > c->vmg_ifo->tt_srpt->nr_of_srpts) {
> +        av_log(s, AV_LOG_ERROR, "Title %d not found\n", c->opt_title);
> +
> +        return AVERROR_STREAM_NOT_FOUND;
> +    }
> +
> +    title_info = c->vmg_ifo->tt_srpt->title[c->opt_title - 1];
> +    if (c->opt_angle > title_info.nr_of_angles) {
> +        av_log(s, AV_LOG_ERROR, "Angle %d not found\n", c->opt_angle);
> +
> +        return AVERROR_STREAM_NOT_FOUND;
> +    }
> +
> +    if (title_info.nr_of_ptts < 1) {
> +        av_log(s, AV_LOG_ERROR, "Title %d has invalid headers (no PTTs
> found)\n", c->opt_title);
> +
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    if (c->opt_chapter_start > title_info.nr_of_ptts ||
> +       (c->opt_chapter_end > 0 && c->opt_chapter_end >
> title_info.nr_of_ptts)) {
> +        av_log(s, AV_LOG_ERROR, "Chapter (PTT) range [%d, %d] is
> invalid\n",
> +                                c->opt_chapter_start, c->opt_chapter_end);
> +
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    if (!(c->vts_ifo = ifoOpen(c->dvdread, title_info.title_set_nr))) {
> +        av_log(s, AV_LOG_ERROR, "Unable to process IFO structure for VTS
> %d\n",
> +                                title_info.title_set_nr);
> +
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    if (title_info.vts_ttn < 1                                      ||
> +        title_info.vts_ttn > 99                                     ||
> +        title_info.vts_ttn > c->vts_ifo->vts_ptt_srpt->nr_of_srpts  ||
> +        c->vts_ifo->vtsi_mat->nr_of_vts_audio_streams > 8           ||
> +        c->vts_ifo->vtsi_mat->nr_of_vts_subp_streams > 32) {
> +
> +        av_log(s, AV_LOG_ERROR, "Title %d has invalid headers in VTS\n",
> c->opt_title);
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    return 0;
> +}
> +
> +static int dvdvideo_is_cell_promising(AVFormatContext *s, pgc_t *pgc, int
> celln)
> +{
> +    dvd_time_t cell_duration = pgc->cell_playback[celln -
> 1].playback_time;
> +
> +    return cell_duration.second >= 1 || cell_duration.minute >= 1 ||
> cell_duration.hour >= 1;
> +}
> +
> +static int dvdvideo_is_pgc_promising(AVFormatContext *s, pgc_t *pgc)
> +{
> +    for (int i = 1; i <= pgc->nr_of_cells; i++)
> +        if (dvdvideo_is_cell_promising(s, pgc, i))
> +            return 1;
> +
> +    return 0;
> +}
> +
> +static void dvdvideo_play_close(AVFormatContext *s, DVDVideoPlaybackState
> *state)
> +{
> +    if (!state->dvdnav)
> +        return;
> +
> +    /* not allocated by av_malloc() */
> +    if (state->pgc_pg_times_est)
> +        free(state->pgc_pg_times_est);
> +
> +    if (dvdnav_close(state->dvdnav) != DVDNAV_STATUS_OK)
> +        av_log(s, AV_LOG_ERROR, "Unable to close dvdnav successfully,
> dvdnav error: %s\n",
> +                                dvdnav_err_to_string(state->dvdnav));
> +}
> +
> +static int dvdvideo_play_open(AVFormatContext *s, DVDVideoPlaybackState
> *state)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    dvdnav_logger_cb dvdnav_log_cb;
> +    dvdnav_status_t dvdnav_open_status;
> +    int32_t disc_region_mask;
> +    int32_t player_region_mask;
> +    int cur_title, cur_pgcn, cur_pgn;
> +    pgc_t *pgc;
> +
> +    dvdnav_log_cb = (dvdnav_logger_cb) { .pf_log = dvdvideo_libdvdnav_log
> };
> +    dvdnav_open_status = dvdnav_open2(&state->dvdnav, s, &dvdnav_log_cb,
> s->url);
> +
> +    if (!state->dvdnav
>       ||
> +        dvdnav_open_status != DVDNAV_STATUS_OK
>       ||
> +        dvdnav_set_readahead_flag(state->dvdnav, 0) != DVDNAV_STATUS_OK
>        ||
> +        dvdnav_set_PGC_positioning_flag(state->dvdnav, 1) !=
> DVDNAV_STATUS_OK   ||
> +        dvdnav_get_region_mask(state->dvdnav, &disc_region_mask) !=
> DVDNAV_STATUS_OK) {
> +        av_log(s, AV_LOG_ERROR, "Unable to open the DVD for playback\n");
> +
> +        goto end_dvdnav_error;
> +    }
> +
> +    player_region_mask = c->opt_region > 0 ? (1 << (c->opt_region - 1)) :
> disc_region_mask;
> +    if (dvdnav_set_region_mask(state->dvdnav, player_region_mask) !=
> DVDNAV_STATUS_OK) {
> +        av_log(s, AV_LOG_ERROR, "Unable to set the playback region code
> %d\n", c->opt_region);
> +
> +        goto end_dvdnav_error;
> +    }
> +
> +    if (c->opt_pgc > 0 && c->opt_pg > 0) {
> +        if (dvdnav_program_play(state->dvdnav, c->opt_title, c->opt_pgc,
> c->opt_pg) != DVDNAV_STATUS_OK) {
> +            av_log(s, AV_LOG_ERROR, "Unable to start playback at title
> %d, PGC %d, PG %d\n",
> +                                    c->opt_title, c->opt_pgc, c->opt_pg);
> +
> +            goto end_dvdnav_error;
> +        }
> +
> +        state->pgcn = c->opt_pgc;
> +        state->entry_pgn = c->opt_pg;
> +    } else {
> +        if (dvdnav_part_play(state->dvdnav, c->opt_title,
> c->opt_chapter_start) != DVDNAV_STATUS_OK ||
> +            dvdnav_current_title_program(state->dvdnav, &cur_title,
> &cur_pgcn, &cur_pgn) != DVDNAV_STATUS_OK) {
> +            av_log(s, AV_LOG_ERROR, "Unable to start playback at title
> %d, chapter (PTT) %d\n",
> +                                    c->opt_title, c->opt_chapter_start);
> +
> +            goto end_dvdnav_error;
> +        }
> +
> +        state->pgcn = cur_pgcn;
> +        state->entry_pgn = cur_pgn;
> +    }
> +
> +    pgc = c->vts_ifo->vts_pgcit->pgci_srp[state->pgcn - 1].pgc;
> +
> +    if (pgc->pg_playback_mode != 0) {
> +        av_log(s, AV_LOG_ERROR, "Non-sequential PGCs, such as shuffles,
> are not supported\n");
> +
> +        return AVERROR_PATCHWELCOME;
> +    }
> +
> +    if (c->opt_trim && !dvdvideo_is_pgc_promising(s, pgc)) {
> +        av_log(s, AV_LOG_ERROR, "Title %d, PGC %d looks empty (may
> consist of padding cells), "
> +                                "if you want to try anyway, disable the
> -trim option\n",
> +                                c->opt_title, state->pgcn);
> +
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    if (dvdnav_angle_change(state->dvdnav, c->opt_angle) !=
> DVDNAV_STATUS_OK) {
> +        av_log(s, AV_LOG_ERROR, "Unable to start playback at angle %d\n",
> c->opt_angle);
> +
> +        goto end_dvdnav_error;
> +    }
> +
> +    /* dvdnav_describe_title_chapters() performs several validations on
> the title structure */
> +    /* take advantage of this side effect to increase chances of a safe
> navigation path */
> +    state->pgc_nb_pg_est = dvdnav_describe_title_chapters(state->dvdnav,
> c->opt_title,
> +
> &state->pgc_pg_times_est,
> +
> &state->pgc_duration_est);
> +
> +    /* dvdnav returning 0 PGs is documented as an error condition */
> +    if (!state->pgc_nb_pg_est) {
> +        av_log(s, AV_LOG_ERROR, "Unable to read chapter information for
> title %d\n", c->opt_title);
> +
> +        goto end_dvdnav_error;
> +    }
> +
> +    state->nav_pts = dvdnav_get_current_time(state->dvdnav);
> +    state->vtsn = c->vmg_ifo->tt_srpt->title[c->opt_title -
> 1].title_set_nr;
> +    state->pgc = pgc;
> +
> +    return 0;
> +
> +end_dvdnav_error:
> +    if (state->dvdnav)
> +        av_log(s, AV_LOG_ERROR, "dvdnav error: %s\n",
> dvdnav_err_to_string(state->dvdnav));
> +    else
> +        av_log(s, AV_LOG_ERROR, "dvdnav could not be initialized\n");
> +
> +    return AVERROR_EXTERNAL;
> +}
> +
> +static int dvdvideo_play_next_ps_block(AVFormatContext *s,
> DVDVideoPlaybackState *state,
> +                                       uint8_t *buf, int buf_size,
> +                                       int *p_nav_event,
> +                                       void (*flush_cb)(AVFormatContext
> *s))
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    uint8_t nav_buf[DVDVIDEO_BLOCK_SIZE] = {0};
> +    int nav_event;
> +    int nav_len;
> +
> +    dvdnav_vts_change_event_t *e_vts;
> +    dvdnav_cell_change_event_t *e_cell;
> +    int cur_title, cur_pgcn, cur_pgn, cur_angle, cur_title_unused,
> cur_ptt, cur_nb_angles;
> +    int is_cell_promising = 0;
> +    pci_t *e_pci;
> +    dsi_t *e_dsi;
> +
> +    if (buf_size != DVDVIDEO_BLOCK_SIZE) {
> +        av_log(s, AV_LOG_ERROR, "Invalid buffer size (expected=%d
> actual=%d)\n",
> +                                DVDVIDEO_BLOCK_SIZE, buf_size);
> +
> +        return AVERROR(EINVAL);
> +    }
> +
> +    for (int i = 0; i < DVDVIDEO_MAX_PS_SEARCH_BLOCKS; i++) {
> +        if (ff_check_interrupt(&s->interrupt_callback))
> +            return AVERROR_EXIT;
> +
> +        if (dvdnav_get_next_block(state->dvdnav, nav_buf, &nav_event,
> &nav_len) != DVDNAV_STATUS_OK) {
> +            av_log(s, AV_LOG_ERROR, "Unable to read next block of PGC\n");
> +
> +            goto end_dvdnav_error;
> +        }
> +
> +        /* some discs follow NOPs with a premature stop event */
> +        if (nav_event == DVDNAV_STOP)
> +            return AVERROR_EOF;
> +
> +        if (nav_len > DVDVIDEO_BLOCK_SIZE) {
> +            av_log(s, AV_LOG_ERROR, "Invalid block size (expected<=%d
> actual=%d)\n",
> +                                    DVDVIDEO_BLOCK_SIZE, nav_len);
> +
> +            return AVERROR_INVALIDDATA;
> +        }
> +
> +        if (dvdnav_current_title_info(state->dvdnav, &cur_title,
> &cur_ptt) != DVDNAV_STATUS_OK) {
> +            av_log(s, AV_LOG_ERROR, "Unable to determine current title
> coordinates\n");
> +
> +            goto end_dvdnav_error;
> +        }
> +
> +        /* we somehow navigated to a menu */
> +        if (cur_title == 0 || !dvdnav_is_domain_vts(state->dvdnav))
> +            return AVERROR_EOF;
> +
> +        if (dvdnav_current_title_program(state->dvdnav,
> &cur_title_unused, &cur_pgcn, &cur_pgn) != DVDNAV_STATUS_OK) {
> +            av_log(s, AV_LOG_ERROR, "Unable to determine current PGC
> coordinates\n");
> +
> +            goto end_dvdnav_error;
> +        }
> +
> +        /* we somehow left the PGC */
> +        if (state->in_pgc && cur_pgcn != state->pgcn)
> +            return AVERROR_EOF;
> +
> +        if (dvdnav_get_angle_info(state->dvdnav, &cur_angle,
> &cur_nb_angles) != DVDNAV_STATUS_OK) {
> +            av_log(s, AV_LOG_ERROR, "Unable to determine current video
> angle\n");
> +
> +            goto end_dvdnav_error;
> +        }
> +
> +        av_log(s, nav_event == DVDNAV_BLOCK_OK ? AV_LOG_TRACE :
> AV_LOG_DEBUG,
> +               "new block: i=%d nav_event=%d nav_len=%d cur_title=%d "
> +               "cur_ptt=%d cur_angle=%d cur_celln=%d cur_pgcn=%d
> cur_pgn=%d "
> +               "play_in_vts=%d play_in_pgc=%d play_in_ps=%d\n",
> +               i, nav_event, nav_len, cur_title,
> +               cur_ptt, cur_angle, state->celln, cur_pgcn, cur_pgn,
> +               state->in_vts, state->in_pgc, state->in_ps);
> +
> +        switch (nav_event) {
> +            case DVDNAV_VTS_CHANGE:
> +                if (state->in_vts)
> +                    return AVERROR_EOF;
> +
> +                e_vts = (dvdnav_vts_change_event_t *) nav_buf;
> +
> +                if (e_vts->new_vtsN == state->vtsn && e_vts->new_domain
> == DVD_DOMAIN_VTSTitle)
> +                    state->in_vts = 1;
> +
> +                continue;
> +            case DVDNAV_CELL_CHANGE:
> +                if (!state->in_vts)
> +                    continue;
> +
> +                e_cell = (dvdnav_cell_change_event_t *) nav_buf;
> +                is_cell_promising = !c->opt_trim ||
> dvdvideo_is_cell_promising(s, state->pgc, e_cell->cellN);
> +
> +                av_log(s, AV_LOG_DEBUG, "new cell: prev=%d new=%d
> promising=%d\n",
> +                                        state->celln, e_cell->cellN,
> is_cell_promising);
> +
> +                if (!state->in_ps && !state->in_pgc) {
> +                    if (cur_title == c->opt_title       &&
> +                        cur_ptt == c->opt_chapter_start &&
> +                        cur_pgcn == state->pgcn         &&
> +                        cur_pgn == state->entry_pgn     &&
> +                        is_cell_promising) {
> +                        state->in_pgc = 1;
> +                    }
> +
> +                    if (c->opt_trim && !is_cell_promising)
> +                        av_log(s, AV_LOG_INFO, "Skipping padding cell
> #%d\n", e_cell->cellN);
> +                } else if (state->celln >= e_cell->cellN || state->pgn >
> cur_pgn) {
> +                    return AVERROR_EOF;
> +                }
> +
> +                state->celln = e_cell->cellN;
> +                state->ptt = cur_ptt;
> +                state->pgn = cur_pgn;
> +                state->nb_cells_played++;
> +
> +                continue;
> +            case DVDNAV_NAV_PACKET:
> +                if (!state->in_pgc)
> +                    continue;
> +
> +                if ((state->ptt > 0 && state->ptt > cur_ptt) ||
> +                    (c->opt_chapter_end > 0 && cur_ptt >
> c->opt_chapter_end)) {
> +                    return AVERROR_EOF;
> +                }
> +
> +                e_pci = dvdnav_get_current_nav_pci(state->dvdnav);
> +                e_dsi = dvdnav_get_current_nav_dsi(state->dvdnav);
> +
> +                if (e_pci == NULL || e_dsi == NULL ||
> +                    e_pci->pci_gi.vobu_s_ptm > e_pci->pci_gi.vobu_e_ptm) {
> +
> +                    av_log(s, AV_LOG_ERROR, "Invalid NAV packet\n");
> +                    return AVERROR_INVALIDDATA;
> +                }
> +
> +                state->vobu_duration = e_pci->pci_gi.vobu_e_ptm -
> e_pci->pci_gi.vobu_s_ptm;
> +                state->pgc_elapsed += state->vobu_duration;
> +                state->nav_pts = dvdnav_get_current_time(state->dvdnav);
> +                state->ptt = cur_ptt;
> +                state->pgn = cur_pgn;
> +
> +                av_log(s, AV_LOG_DEBUG,
> +                       "NAV pack: s_ptm=%d e_ptm=%d "
> +                       "scr=%d lbn=%d vobu_duration=%d nav_pts=%ld\n",
> +                       e_pci->pci_gi.vobu_s_ptm, e_pci->pci_gi.vobu_e_ptm,
> +                       e_dsi->dsi_gi.nv_pck_scr,
> +                       e_pci->pci_gi.nv_pck_lbn, state->vobu_duration,
> state->nav_pts);
> +
> +                if (!state->in_ps) {
> +                    av_log(s, AV_LOG_DEBUG, "navigation: locked to
> program stream\n");
> +
> +                    state->in_ps = 1;
> +                } else {
> +                    if (state->vobu_e_ptm != e_pci->pci_gi.vobu_s_ptm) {
> +                        if (flush_cb)
> +                            flush_cb(s);
> +
> +                        state->ts_offset += state->vobu_e_ptm -
> e_pci->pci_gi.vobu_s_ptm;
> +                    }
> +                }
> +
> +                state->vobu_e_ptm = e_pci->pci_gi.vobu_e_ptm;
> +
> +                (*p_nav_event) = nav_event;
> +
> +                return nav_len;
> +            case DVDNAV_BLOCK_OK:
> +                if (!state->in_ps) {
> +                    if (state->in_pgc)
> +                        i = 0; /* necessary in case we are skipping junk
> cells at the beginning */
> +                    continue;
> +                }
> +
> +                if (nav_len != DVDVIDEO_BLOCK_SIZE) {
> +                    av_log(s, AV_LOG_ERROR, "Invalid MPEG block size
> (expected=%d actual=%d)\n",
> +                                            DVDVIDEO_BLOCK_SIZE, nav_len);
> +
> +                    return AVERROR_INVALIDDATA;
> +                }
> +
> +                if (cur_angle != c->opt_angle) {
> +                    av_log(s, AV_LOG_ERROR, "Unexpected angle change
> (expected=%d new=%d)\n",
> +                                            c->opt_angle, cur_angle);
> +
> +                    return AVERROR_INPUT_CHANGED;
> +                }
> +
> +                memcpy(buf, &nav_buf, nav_len);
> +
> +                /* in case NAV packet is missed */
> +                state->ptt = cur_ptt;
> +                state->pgn = cur_pgn;
> +
> +                (*p_nav_event) = nav_event;
> +
> +                return nav_len;
> +            case DVDNAV_STILL_FRAME:
> +            case DVDNAV_WAIT:
> +            case DVDNAV_HOP_CHANNEL:
> +            case DVDNAV_HIGHLIGHT:
> +                if (state->in_ps)
> +                    return AVERROR_EOF;
> +
> +                if (nav_event == DVDNAV_STILL_FRAME) {
> +                    if (dvdnav_still_skip(state->dvdnav) !=
> DVDNAV_STATUS_OK) {
> +                        av_log(s, AV_LOG_ERROR, "Unable to skip still
> image\n");
> +
> +                        goto end_dvdnav_error;
> +                    }
> +                }
> +
> +                if (nav_event == DVDNAV_WAIT) {
> +                    if (dvdnav_wait_skip(state->dvdnav) !=
> DVDNAV_STATUS_OK) {
> +                        av_log(s, AV_LOG_ERROR, "Unable to skip WAIT
> event\n");
> +
> +                        goto end_dvdnav_error;
> +                    }
> +                }
> +
> +                continue;
> +            case DVDNAV_STOP:
> +                return AVERROR_EOF;
> +            default:
> +                continue;
> +        }
> +    }
> +
> +    av_log(s, AV_LOG_ERROR, "Unable to find next program stream block\n");
> +
> +    return AVERROR_INVALIDDATA;
> +
> +end_dvdnav_error:
> +    av_log(s, AV_LOG_ERROR, "dvdnav error (title=%d pgc=%d pg=%d
> cell=%d): %s\n",
> +                            cur_title, cur_pgcn, cur_pgn, state->celln,
> +                            dvdnav_err_to_string(state->dvdnav));
> +
> +    return AVERROR_EXTERNAL;
> +}
> +
> +static int dvdvideo_pgc_preindex(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    int ret = 0, interrupt = 0;
> +    int nb_chapters = 0, last_ptt = c->opt_chapter_start;
> +    uint64_t cur_chapter_offset = 0, cur_chapter_duration = 0;
> +    DVDVideoPlaybackState state = {0};
> +
> +    uint8_t nav_buf[DVDVIDEO_BLOCK_SIZE];
> +    int nav_event;
> +
> +    if (c->opt_chapter_start == c->opt_chapter_end)
> +        return ret;
> +
> +    av_log(s, AV_LOG_INFO,
> +           "Indexing chapter markers, this will take a long time. Please
> wait...\n");
> +
> +    if ((ret = dvdvideo_play_open(s, &state)) < 0 ||
> state.pgc->nr_of_programs == 1)
> +        return ret;
> +
> +    while (!(interrupt = ff_check_interrupt(&s->interrupt_callback))) {
> +        ret = dvdvideo_play_next_ps_block(s, &state, nav_buf,
> DVDVIDEO_BLOCK_SIZE,
> +                                          &nav_event, NULL);
> +        if (ret < 0 && ret != AVERROR_EOF)
> +            goto end_close;
> +
> +        if (nav_event != DVDNAV_NAV_PACKET && ret != AVERROR_EOF)
> +            continue;
> +
> +        if (state.ptt == last_ptt) {
> +            cur_chapter_duration += state.vobu_duration;
> +            /* ensure we add the last chapter */
> +            if (ret != AVERROR_EOF)
> +                continue;
> +        }
> +
> +        if (!avpriv_new_chapter(s, nb_chapters, DVDVIDEO_TIME_BASE_Q,
> cur_chapter_offset,
> +                                cur_chapter_offset +
> cur_chapter_duration, NULL)) {
> +            ret = AVERROR(ENOMEM);
> +            goto end_close;
> +        }
> +
> +        nb_chapters++;
> +        cur_chapter_offset += cur_chapter_duration;
> +        cur_chapter_duration = state.vobu_duration;
> +        last_ptt = state.ptt;
> +
> +        if (ret == AVERROR_EOF)
> +            break;
> +    }
> +
> +    if (interrupt) {
> +        ret = AVERROR_EXIT;
> +        goto end_close;
> +    }
> +
> +    if (ret < 0 && ret != AVERROR_EOF)
> +        goto end_close;
> +
> +    s->duration = av_rescale_q(state.pgc_elapsed, DVDVIDEO_TIME_BASE_Q,
> AV_TIME_BASE_Q);
> +    c->duration_ptm = state.pgc_elapsed;
> +
> +    av_log(s, AV_LOG_INFO, "Chapter marker indexing complete\n");
> +    ret = 0;
> +
> +end_close:
> +    dvdvideo_play_close(s, &state);
> +
> +    return ret;
> +}
> +
> +static int dvdvideo_pgc_chapters_setup(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    uint64_t time_prev = 0;
> +    int64_t total_duration = 0;
> +
> +    int chapter_start = c->opt_chapter_start - 1;
> +    int chapter_end = c->opt_chapter_end > 0 ? c->opt_chapter_end :
> c->play_state.pgc_nb_pg_est - 1;
> +
> +    if (chapter_start == chapter_end || c->play_state.pgc_nb_pg_est == 1)
> {
> +        s->duration = av_rescale_q(c->play_state.pgc_duration_est,
> +                                   DVDVIDEO_TIME_BASE_Q, AV_TIME_BASE_Q);
> +        return 0;
> +    }
> +
> +    for (int i = chapter_start; i < chapter_end; i++) {
> +        uint64_t time_effective = c->play_state.pgc_pg_times_est[i] -
> c->play_state.nav_pts;
> +
> +        if (!avpriv_new_chapter(s, i, DVDVIDEO_TIME_BASE_Q, time_prev,
> time_effective, NULL))
> +            return AVERROR(ENOMEM);
> +
> +        time_prev = time_effective;
> +        total_duration = time_effective;
> +    }
> +
> +    if (c->opt_chapter_start == 1 && c->opt_chapter_end == 0)
> +        s->duration = av_rescale_q(c->play_state.pgc_duration_est,
> +                                   DVDVIDEO_TIME_BASE_Q, AV_TIME_BASE_Q);
> +    else
> +        s->duration = av_rescale_q(total_duration,
> +                                   DVDVIDEO_TIME_BASE_Q, AV_TIME_BASE_Q);
> +
> +    return 0;
> +}
> +
> +static int dvdvideo_video_stream_analyze(AVFormatContext *s, video_attr_t
> video_attr,
> +                                         DVDVideoVTSVideoStreamEntry
> *entry)
> +{
> +    AVRational framerate;
> +    int height = 0;
> +    int width = 0;
> +    int is_pal = video_attr.video_format == 1;
> +
> +    framerate = is_pal ? (AVRational) { 25, 1 } : (AVRational) { 30000,
> 1001 };
> +    height = is_pal ? 576 : 480;
> +
> +    if (height > 0) {
> +        switch (video_attr.picture_size) {
> +            case 0: /* D1 */
> +                width = 720;
> +                break;
> +            case 1: /* 4CIF */
> +                width = 704;
> +                break;
> +            case 2: /* Half D1 */
> +                width = 352;
> +                break;
> +            case 3: /* CIF */
> +                width = 352;
> +                height /= 2;
> +                break;
> +        }
> +    }
> +
> +    if (!width || !height) {
> +        av_log(s, AV_LOG_ERROR, "Invalid video stream parameters in the
> IFO headers, "
> +                                "this could be an authoring error or
> empty title "
> +                                "(video_format=%d picture_size=%d)\n",
> +                                video_attr.video_format,
> video_attr.picture_size);
> +
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    entry->startcode = 0x1E0;
> +    entry->codec_id = !video_attr.mpeg_version ? AV_CODEC_ID_MPEG1VIDEO :
> AV_CODEC_ID_MPEG2VIDEO;
> +    entry->width = width;
> +    entry->height = height;
> +    entry->dar = video_attr.display_aspect_ratio ? (AVRational) { 16, 9 }
> : (AVRational) { 4, 3 };
> +    entry->framerate = framerate;
> +    entry->has_cc = !is_pal && (video_attr.line21_cc_1 ||
> video_attr.line21_cc_2);
> +
> +    return 0;
> +}
> +
> +static int dvdvideo_video_stream_add(AVFormatContext *s,
> +                                     DVDVideoVTSVideoStreamEntry *entry,
> +                                     enum AVStreamParseType need_parsing)
> +{
> +    AVStream *st;
> +    FFStream *sti;
> +
> +    st = avformat_new_stream(s, NULL);
> +    if (!st)
> +        return AVERROR(ENOMEM);
> +
> +    st->id = entry->startcode;
> +    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
> +    st->codecpar->codec_id = entry->codec_id;
> +    st->codecpar->width = entry->width;
> +    st->codecpar->height = entry->height;
> +    st->codecpar->format = AV_PIX_FMT_YUV420P;
> +    st->codecpar->color_range = AVCOL_RANGE_MPEG;
> +
> +    st->codecpar->framerate = entry->framerate;
> +#if FF_API_R_FRAME_RATE
> +    st->r_frame_rate = entry->framerate;
> +#endif
> +    st->avg_frame_rate = entry->framerate;
> +
> +    sti = ffstream(st);
> +    sti->request_probe = 0;
> +    sti->need_parsing = need_parsing;
> +    sti->display_aspect_ratio = entry->dar;
> +    sti->avctx->framerate = entry->framerate;
> +
> +    if (entry->has_cc)
> +        sti->avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
> +
> +    avpriv_set_pts_info(st, DVDVIDEO_PTS_WRAP_BITS,
> +                        DVDVIDEO_TIME_BASE_Q.num,
> DVDVIDEO_TIME_BASE_Q.den);
> +
> +    return 0;
> +}
> +
> +static int dvdvideo_video_stream_setup(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    int ret = 0;
> +    DVDVideoVTSVideoStreamEntry entry = {0};
> +
> +    if ((ret = dvdvideo_video_stream_analyze(s,
> c->vts_ifo->vtsi_mat->vts_video_attr, &entry)) < 0 ||
> +        (ret = dvdvideo_video_stream_add(c->mpeg_ctx, &entry,
> AVSTREAM_PARSE_FULL)) < 0 ||
> +        (ret = dvdvideo_video_stream_add(s, &entry,
> AVSTREAM_PARSE_HEADERS)) < 0) {
> +
> +        av_log(s, AV_LOG_ERROR, "Unable to add video stream\n");
> +        return ret;
> +    }
> +
> +    return ret;
> +}
> +
> +static int dvdvideo_audio_stream_analyze(AVFormatContext *s, audio_attr_t
> audio_attr,
> +                                         uint16_t audio_control,
> DVDVideoPGCAudioStreamEntry *entry)
> +{
> +    int startcode = 0;
> +    enum AVCodecID codec_id = AV_CODEC_ID_NONE;
> +    int sample_fmt = AV_SAMPLE_FMT_NONE;
> +    int sample_rate = 0;
> +    int bit_depth = 0;
> +    int nb_channels = 0;
> +    AVChannelLayout ch_layout = (AVChannelLayout) {0};
> +    char lang_dvd[3] = {0};
> +
> +    int position = (audio_control & 0x7F00) >> 8;
> +
> +    /* XXX(PATCHWELCOME): SDDS is not supported due to lack of sample
> material */
> +    switch (audio_attr.audio_format) {
> +        case 0: /* AC3 */
> +            codec_id = AV_CODEC_ID_AC3;
> +            sample_fmt = AV_SAMPLE_FMT_FLTP;
> +            sample_rate = 48000;
> +            startcode = 0x80 + position;
> +            break;
> +        case 2: /* MP1 */
> +            codec_id = AV_CODEC_ID_MP1;
> +            sample_fmt = audio_attr.quantization ? AV_SAMPLE_FMT_S32 :
> AV_SAMPLE_FMT_S16;
> +            sample_rate = 48000;
> +            bit_depth = audio_attr.quantization ? 20 : 16;
> +            startcode = 0x1C0 + position;
> +            break;
> +        case 3: /* MP2 */
> +            codec_id = AV_CODEC_ID_MP2;
> +            sample_fmt = audio_attr.quantization ? AV_SAMPLE_FMT_S32 :
> AV_SAMPLE_FMT_S16;
> +            sample_rate = 48000;
> +            bit_depth = audio_attr.quantization ? 20 : 16;
> +            startcode = 0x1C0 + position;
> +            break;
> +        case 4: /* DVD PCM */
> +            codec_id = AV_CODEC_ID_PCM_DVD;
> +            sample_fmt = audio_attr.quantization ? AV_SAMPLE_FMT_S32 :
> AV_SAMPLE_FMT_S16;
> +            sample_rate = audio_attr.sample_frequency ? 96000 : 48000;
> +            bit_depth = audio_attr.quantization == 2 ? 24 :
> (audio_attr.quantization ? 20 : 16);
> +            startcode = 0xA0 + position;
> +            break;
> +        case 6: /* DCA */
> +            codec_id = AV_CODEC_ID_DTS;
> +            sample_fmt = AV_SAMPLE_FMT_FLTP;
> +            sample_rate = 48000;
> +            bit_depth = audio_attr.quantization == 2 ? 24 :
> (audio_attr.quantization ? 20 : 16);
> +            startcode = 0x88 + position;
> +            break;
> +    }
> +
> +    nb_channels = audio_attr.channels + 1;
> +
> +    if (codec_id == AV_CODEC_ID_NONE         ||
> +            startcode == 0                   ||
> +            sample_fmt == AV_SAMPLE_FMT_NONE ||
> +            sample_rate == 0                 ||
> +            nb_channels == 0) {
> +
> +        av_log(s, AV_LOG_ERROR, "Invalid audio stream parameters in the
> IFO headers, "
> +                                "this could be an authoring error or
> dummy title "
> +                                "(stream position %d in IFO)\n",
> position);
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    if (nb_channels == 2)
> +        ch_layout = (AVChannelLayout) AV_CHANNEL_LAYOUT_STEREO;
> +    else if (nb_channels == 6)
> +        ch_layout = (AVChannelLayout) AV_CHANNEL_LAYOUT_5POINT1;
> +    else if (nb_channels == 7)
> +        ch_layout = (AVChannelLayout) AV_CHANNEL_LAYOUT_6POINT1;
> +    else if (nb_channels == 8)
> +        ch_layout = (AVChannelLayout) AV_CHANNEL_LAYOUT_7POINT1;
> +
> +
> +    if (audio_attr.application_mode == 1) {
> +        entry->disposition |= AV_DISPOSITION_KARAOKE;
> +
> +        av_log(s, AV_LOG_WARNING, "Extended karaoke metadata is not
> supported at this time "
> +                                  "(stream id=%d)\n", startcode);
> +    }
> +
> +    if (audio_attr.code_extension == 2)
> +        entry->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
> +    if (audio_attr.code_extension == 3 || audio_attr.code_extension == 4)
> +        entry->disposition |= AV_DISPOSITION_COMMENT;
> +
> +    AV_WB16(lang_dvd, audio_attr.lang_code);
> +
> +    entry->startcode = startcode;
> +    entry->codec_id = codec_id;
> +    entry->sample_rate = sample_rate;
> +    entry->bit_depth = bit_depth;
> +    entry->nb_channels = nb_channels;
> +    entry->ch_layout = ch_layout;
> +    entry->lang_iso = ff_convert_lang_to(lang_dvd, AV_LANG_ISO639_2_BIBL);
> +
> +    return 0;
> +}
> +
> +static int dvdvideo_audio_stream_add(AVFormatContext *s,
> DVDVideoPGCAudioStreamEntry *entry,
> +                                     enum AVStreamParseType need_parsing)
> +{
> +    AVStream *st;
> +    FFStream *sti;
> +
> +    st = avformat_new_stream(s, NULL);
> +    if (!st)
> +        return AVERROR(ENOMEM);
> +
> +    st->id = entry->startcode;
> +    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
> +    st->codecpar->codec_id = entry->codec_id;
> +    st->codecpar->format = entry->sample_fmt;
> +    st->codecpar->sample_rate = entry->sample_rate;
> +    st->codecpar->bits_per_coded_sample = entry->bit_depth;
> +    st->codecpar->bits_per_raw_sample = entry->bit_depth;
> +    st->codecpar->ch_layout = entry->ch_layout;
> +    st->codecpar->ch_layout.nb_channels = entry->nb_channels;
> +    st->disposition = entry->disposition;
> +
> +    if (entry->lang_iso)
> +        av_dict_set(&st->metadata, "language", entry->lang_iso, 0);
> +
> +    sti = ffstream(st);
> +    sti->request_probe = 0;
> +    sti->need_parsing = need_parsing;
> +
> +    avpriv_set_pts_info(st, DVDVIDEO_PTS_WRAP_BITS,
> +                        DVDVIDEO_TIME_BASE_Q.num,
> DVDVIDEO_TIME_BASE_Q.den);
> +
> +    return 0;
> +}
> +
> +static int dvdvideo_audio_stream_add_all(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    int ret = 0;
> +
> +    for (int i = 0; i < c->vts_ifo->vtsi_mat->nr_of_vts_audio_streams;
> i++) {
> +        DVDVideoPGCAudioStreamEntry entry = {0};
> +
> +        if (!(c->play_state.pgc->audio_control[i] & 0x8000))
> +            continue;
> +
> +        if ((ret = dvdvideo_audio_stream_analyze(s,
> c->vts_ifo->vtsi_mat->vts_audio_attr[i],
> +
>  c->play_state.pgc->audio_control[i], &entry)) < 0)
> +            goto break_error;
> +
> +        /* IFO structures can declare duplicate entries for the same
> startcode */
> +        for (int j = 0; j < s->nb_streams; j++)
> +            if (s->streams[j]->id == entry.startcode)
> +                continue;
> +
> +        if ((ret = dvdvideo_audio_stream_add(c->mpeg_ctx, &entry,
> AVSTREAM_PARSE_FULL)) < 0 ||
> +            (ret = dvdvideo_audio_stream_add(s, &entry,
> AVSTREAM_PARSE_HEADERS)) < 0)
> +            goto break_error;
> +
> +        continue;
> +
> +break_error:
> +        av_log(s, AV_LOG_ERROR, "Unable to add audio stream at position
> %d\n", i);
> +        return ret;
> +    }
> +
> +    return ret;
> +}
> +
> +static int dvdvideo_subp_stream_analyze(AVFormatContext *s, uint32_t
> offset, subp_attr_t subp_attr,
> +                                        DVDVideoPGCSubtitleStreamEntry
> *entry)
> +{
> +    char lang_dvd[3] = {0};
> +
> +    entry->startcode = 0x20 + (offset & 0x1F);
> +
> +    if (subp_attr.lang_extension == 9)
> +        entry->disposition |= AV_DISPOSITION_FORCED;
> +
> +    AV_WB16(lang_dvd, subp_attr.lang_code);
> +    entry->lang_iso = ff_convert_lang_to(lang_dvd, AV_LANG_ISO639_2_BIBL);
> +
> +    return 0;
> +}
> +
> +static int dvdvideo_subp_stream_add(AVFormatContext *s,
> DVDVideoPGCSubtitleStreamEntry *entry,
> +                                    enum AVStreamParseType need_parsing)
> +{
> +    AVStream *st;
> +    FFStream *sti;
> +    int ret = 0;
> +
> +    st = avformat_new_stream(s, NULL);
> +    if (!st)
> +        return AVERROR(ENOMEM);
> +
> +    st->id = entry->startcode;
> +    st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
> +    st->codecpar->codec_id = AV_CODEC_ID_DVD_SUBTITLE;
> +
> +    if (entry->lang_iso)
> +        av_dict_set(&st->metadata, "language", entry->lang_iso, 0);
> +
> +    av_dict_set(&st->metadata, "VIEWPORT",
> dvdvideo_subp_viewport_labels[entry->viewport], 0);
> +
> +    st->disposition = entry->disposition;
> +
> +    sti = ffstream(st);
> +    sti->request_probe = 0;
> +    sti->need_parsing = need_parsing;
> +
> +    avpriv_set_pts_info(st, DVDVIDEO_PTS_WRAP_BITS,
> +                        DVDVIDEO_TIME_BASE_Q.num,
> DVDVIDEO_TIME_BASE_Q.den);
> +
> +    return ret;
> +}
> +
> +static int dvdvideo_subp_stream_add_internal(AVFormatContext *s, uint32_t
> offset,
> +                                             subp_attr_t subp_attr,
> +                                             enum
> DVDVideoSubpictureViewport viewport)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    int ret = 0;
> +    DVDVideoPGCSubtitleStreamEntry entry = {0};
> +
> +    entry.viewport = viewport;
> +
> +    if ((ret = dvdvideo_subp_stream_analyze(s, offset, subp_attr,
> &entry)) < 0)
> +        goto end_error;
> +
> +    /* IFO structures can declare duplicate entries for the same
> startcode */
> +    for (int i = 0; i < s->nb_streams; i++)
> +        if (s->streams[i]->id == entry.startcode)
> +            goto end;
> +
> +    if ((ret = dvdvideo_subp_stream_add(c->mpeg_ctx, &entry,
> AVSTREAM_PARSE_FULL)) < 0 ||
> +        (ret = dvdvideo_subp_stream_add(s, &entry,
> AVSTREAM_PARSE_HEADERS)) < 0)
> +        goto end_error;
> +
> +    goto end;
> +
> +end_error:
> +    av_log(s, AV_LOG_ERROR, "Unable to add subtitle stream\n");
> +
> +end:
> +    return ret;
> +}
> +
> +static int dvdvideo_subp_stream_add_all(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    if (!c->vts_ifo->vtsi_mat->nr_of_vts_subp_streams)
> +        return 0;
> +
> +    for (int i = 0; i < c->vts_ifo->vtsi_mat->nr_of_vts_subp_streams;
> i++) {
> +        int ret = 0;
> +        uint32_t subp_control;
> +        subp_attr_t subp_attr;
> +        video_attr_t video_attr;
> +
> +        subp_control = c->play_state.pgc->subp_control[i];
> +        if (!(subp_control & 0x80000000))
> +            continue;
> +
> +        /* there can be several presentations for one SPU */
> +        /* the DAR check is flexible in order to support weird authoring
> */
> +        video_attr = c->vts_ifo->vtsi_mat->vts_video_attr;
> +        subp_attr = c->vts_ifo->vtsi_mat->vts_subp_attr[i];
> +
> +        /* 4:3 */
> +        if (!video_attr.display_aspect_ratio) {
> +            if ((ret = dvdvideo_subp_stream_add_internal(s, subp_control
> >> 24, subp_attr,
> +
>  DVDVIDEO_SUBP_VIEWPORT_FULLSCREEN)) < 0)
> +                return ret;
> +
> +            continue;
> +        }
> +
> +        /* 16:9 */
> +        if ((    ret = dvdvideo_subp_stream_add_internal(s, subp_control
> >> 16, subp_attr,
> +
>  DVDVIDEO_SUBP_VIEWPORT_WIDESCREEN)) < 0)
> +            return ret;
> +
> +        /* 16:9 letterbox */
> +        if (video_attr.permitted_df == 2 || video_attr.permitted_df == 0)
> +            if ((ret = dvdvideo_subp_stream_add_internal(s, subp_control
> >> 8, subp_attr,
> +
>  DVDVIDEO_SUBP_VIEWPORT_LETTERBOX)) < 0)
> +                return ret;
> +
> +        /* 16:9 pan-and-scan */
> +        if (video_attr.permitted_df == 1 || video_attr.permitted_df == 0)
> +            if ((ret = dvdvideo_subp_stream_add_internal(s, subp_control,
> subp_attr,
> +
>  DVDVIDEO_SUBP_VIEWPORT_PANSCAN)) < 0)
> +                return ret;
> +    }
> +
> +    return 0;
> +}
> +
> +static void dvdvideo_subdemux_flush(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    if (!c->segment_started)
> +        return;
> +
> +    av_log(s, AV_LOG_DEBUG, "flushing sub-demuxer\n");
> +    avio_flush(&c->mpeg_pb.pub);
> +    ff_read_frame_flush(c->mpeg_ctx);
> +    c->segment_started = 0;
> +}
> +
> +static int dvdvideo_subdemux_read_data(void *opaque, uint8_t *buf, int
> buf_size)
> +{
> +    AVFormatContext *s = opaque;
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    int ret = 0;
> +    int nav_event;
> +
> +    if (c->play_end)
> +        return AVERROR_EOF;
> +
> +    ret = dvdvideo_play_next_ps_block(opaque, &c->play_state, buf,
> buf_size,
> +                                      &nav_event,
> dvdvideo_subdemux_flush);
> +
> +    if (ret == AVERROR_EOF) {
> +        c->mpeg_pb.pub.eof_reached = 1;
> +        c->play_end = 1;
> +
> +        return AVERROR_EOF;
> +    }
> +
> +    if (ret >= 0 && nav_event == DVDNAV_NAV_PACKET)
> +        return FFERROR_REDO;
> +
> +    return ret;
> +}
> +
> +static void dvdvideo_subdemux_close(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    av_freep(&c->mpeg_pb.pub.buffer);
> +    av_freep(&c->mpeg_pb);
> +    avformat_close_input(&c->mpeg_ctx);
> +}
> +
> +static int dvdvideo_subdemux_open(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    int ret = 0;
> +
> +    if (!(c->mpeg_fmt = av_find_input_format("mpeg")))
> +        return AVERROR_DEMUXER_NOT_FOUND;
> +
> +    if (!(c->mpeg_ctx = avformat_alloc_context()))
> +        return AVERROR(ENOMEM);
> +
> +    if (!(c->mpeg_buf = av_mallocz(DVDVIDEO_BLOCK_SIZE))) {
> +        avformat_free_context(c->mpeg_ctx);
> +        c->mpeg_ctx = NULL;
> +
> +        return AVERROR(ENOMEM);
> +    }
> +
> +    ffio_init_context(&c->mpeg_pb, c->mpeg_buf, DVDVIDEO_BLOCK_SIZE, 0, s,
> +                      dvdvideo_subdemux_read_data, NULL, NULL);
> +    c->mpeg_pb.pub.seekable = 0;
> +
> +    if ((ret = ff_copy_whiteblacklists(c->mpeg_ctx, s)) < 0) {
> +        avformat_free_context(c->mpeg_ctx);
> +        c->mpeg_ctx = NULL;
> +
> +        return ret;
> +    }
> +
> +    c->mpeg_ctx->flags = AVFMT_FLAG_CUSTOM_IO | AVFMT_FLAG_GENPTS;
> +    c->mpeg_ctx->ctx_flags |= AVFMTCTX_UNSEEKABLE;
> +    c->mpeg_ctx->probesize = 0;
> +    c->mpeg_ctx->max_analyze_duration = 0;
> +    c->mpeg_ctx->interrupt_callback = s->interrupt_callback;
> +    c->mpeg_ctx->pb = &c->mpeg_pb.pub;
> +    c->mpeg_ctx->io_open = NULL;
> +
> +    if ((ret = avformat_open_input(&c->mpeg_ctx, "", c->mpeg_fmt, NULL))
> < 0)
> +        c->mpeg_ctx = NULL;
> +
> +    return ret;
> +}
> +
> +static int dvdvideo_read_header(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    int ret = 0;
> +
> +    if (c->opt_title == 0) {
> +        av_log(s, AV_LOG_INFO, "Defaulting to title #1. "
> +                               "This is not always the main feature,
> validation suggested.\n");
> +
> +        c->opt_title = 1;
> +    }
> +
> +    if (c->opt_pgc) {
> +        if (c->opt_pg == 0)
> +            av_log(s, AV_LOG_ERROR, "Invalid coordinates. If -pgc is set,
> -pg must be set too.\n");
> +        else if (c->opt_chapter_start > 1 || c->opt_chapter_end > 0 ||
> c->opt_preindex)
> +            av_log(s, AV_LOG_ERROR, "-pgc is not compatible with the
> -preindex or "
> +                                    "-chapter_start/-chapter_end
> options\n");
> +
> +        return AVERROR(EINVAL);
> +    }
> +
> +    if ((ret = dvdvideo_ifo_open(s)) < 0)
> +        return ret;
> +
> +    if (c->opt_preindex && (ret = dvdvideo_pgc_preindex(s)) < 0)
> +        return ret;
> +
> +    if ((ret = dvdvideo_play_open(s, &c->play_state)) < 0   ||
> +        (ret = dvdvideo_subdemux_open(s)) < 0               ||
> +        (ret = dvdvideo_video_stream_setup(s)) < 0          ||
> +        (ret = dvdvideo_audio_stream_add_all(s)) < 0        ||
> +        (ret = dvdvideo_subp_stream_add_all(s)) < 0)
> +        return ret;
> +
> +    if (!c->opt_preindex)
> +        return dvdvideo_pgc_chapters_setup(s);
> +
> +    return ret;
> +}
> +
> +static int dvdvideo_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    int ret;
> +    enum AVMediaType st_type;
> +    int64_t cur_delta = 0;
> +
> +    if (c->play_end)
> +        return AVERROR_EOF;
> +
> +    ret = av_read_frame(c->mpeg_ctx, pkt);
> +
> +    if (ret < 0)
> +        return ret;
> +
> +    if (!c->segment_started)
> +        c->segment_started = 1;
> +
> +    if (pkt->stream_index >= s->nb_streams) {
> +        av_log(s, AV_LOG_DEBUG, "discarding frame with stream that was
> not in IFO headers "
> +                                "(index=%d)\n", pkt->stream_index);
> +
> +        return FFERROR_REDO;
> +    }
> +
> +    st_type =
> c->mpeg_ctx->streams[pkt->stream_index]->codecpar->codec_type;
> +
> +    if (!c->play_started) {
> +        if (st_type != AVMEDIA_TYPE_VIDEO || pkt->pts == AV_NOPTS_VALUE ||
> +                                             pkt->dts == AV_NOPTS_VALUE ||
> +                                             !(pkt->flags &
> AV_PKT_FLAG_KEY)) {
> +            av_log(s, AV_LOG_VERBOSE, "discarding packet which is not a
> video keyframe or "
> +                                      "with unset PTS/DTS at start\n");
> +            return FFERROR_REDO;
> +        }
> +
> +        c->first_pts = pkt->pts;
> +        c->play_started = 1;
> +
> +        pkt->pts = 0;
> +        pkt->dts = c->play_state.ts_offset - pkt->pts;
> +    } else {
> +        cur_delta = c->play_state.ts_offset - c->first_pts;
> +
> +        if (c->play_state.nb_cells_played == 1 && (pkt->pts ==
> AV_NOPTS_VALUE ||
> +                                                   pkt->dts ==
> AV_NOPTS_VALUE ||
> +                                                   (pkt->pts + cur_delta)
> < 0)) {
> +            av_log(s, AV_LOG_VERBOSE, "discarding packet with negative
> PTS or unset PTS/DTS "
> +                                      "(this is OK at the start of the
> first playback cell)\n");
> +            return FFERROR_REDO;
> +        }
> +
> +        if (pkt->pts != AV_NOPTS_VALUE)
> +            pkt->pts += cur_delta;
> +        if (pkt->dts != AV_NOPTS_VALUE)
> +            pkt->dts += cur_delta;
> +    }
> +
> +    av_log(s, AV_LOG_TRACE, "st=%d pts=%ld dts=%ld ts_offset=%ld
> first_pts=%ld\n",
> +                            pkt->stream_index, pkt->pts, pkt->dts,
> +                            c->play_state.ts_offset, c->first_pts);
> +    if (pkt->pts < 0)
> +        av_log(s, AV_LOG_WARNING, "Invalid frame PTS @ st=%d pts=%ld
> dts=%ld\n",
> +                                  pkt->stream_index, pkt->pts, pkt->dts);
> +
> +    return c->play_end ? AVERROR_EOF : 0;
> +}
> +
> +static int dvdvideo_close(AVFormatContext *s)
> +{
> +    DVDVideoDemuxContext *c = s->priv_data;
> +
> +    dvdvideo_subdemux_close(s);
> +    dvdvideo_play_close(s, &c->play_state);
> +    dvdvideo_ifo_close(s);
> +
> +    return 0;
> +}
> +
> +#define OFFSET(x) offsetof(DVDVideoDemuxContext, x)
> +static const AVOption dvdvideo_options[] = {
> +    {"angle",           "playback angle number",
>           OFFSET(opt_angle),          AV_OPT_TYPE_INT,    { .i64=1 },
>  1,          9,         AV_OPT_FLAG_DECODING_PARAM },
> +    {"chapter_end",     "exit chapter (PTT) number (0=end)",
>           OFFSET(opt_chapter_end),    AV_OPT_TYPE_INT,    { .i64=0 },
>  0,          99,        AV_OPT_FLAG_DECODING_PARAM },
> +    {"chapter_start",   "entry chapter (PTT) number",
>            OFFSET(opt_chapter_start),  AV_OPT_TYPE_INT,    { .i64=1 },
>  1,          99,        AV_OPT_FLAG_DECODING_PARAM },
> +    {"pg",              "entry PG number (0=auto)",
>            OFFSET(opt_pg),             AV_OPT_TYPE_INT,    { .i64=0 },
>  0,          255,       AV_OPT_FLAG_DECODING_PARAM },
> +    {"pgc",             "entry PGC number (0=auto)",
>           OFFSET(opt_pgc),            AV_OPT_TYPE_INT,    { .i64=0 },
>  0,          999,       AV_OPT_FLAG_DECODING_PARAM },
> +    {"preindex",        "enable for accurate chapter markers, slow
> (2-pass read)",  OFFSET(opt_preindex),       AV_OPT_TYPE_BOOL,   { .i64=0
> },     0,          1,         AV_OPT_FLAG_DECODING_PARAM },
> +    {"region",          "playback region number (0=free)",
>           OFFSET(opt_region),         AV_OPT_TYPE_INT,    { .i64=0 },
>  0,          8,         AV_OPT_FLAG_DECODING_PARAM },
> +    {"title",           "title number (0=auto)",
>           OFFSET(opt_title),          AV_OPT_TYPE_INT,    { .i64=0 },
>  0,          99,        AV_OPT_FLAG_DECODING_PARAM },
> +    {"trim",            "trim padding cells from start",
>           OFFSET(opt_trim),           AV_OPT_TYPE_BOOL,   { .i64=1 },
>  0,          1,         AV_OPT_FLAG_DECODING_PARAM },
> +    {NULL}
> +};
> +
> +static const AVClass dvdvideo_class = {
> +    .class_name = "DVD-Video demuxer",
> +    .item_name  = av_default_item_name,
> +    .option     = dvdvideo_options,
> +    .version    = LIBAVUTIL_VERSION_INT
> +};
> +
> +const AVInputFormat ff_dvdvideo_demuxer = {
> +    .name           = "dvdvideo",
> +    .long_name      = NULL_IF_CONFIG_SMALL("DVD-Video"),
> +    .priv_class     = &dvdvideo_class,
> +    .priv_data_size = sizeof(DVDVideoDemuxContext),
> +    .flags          = AVFMT_NOFILE | AVFMT_SHOW_IDS | AVFMT_TS_DISCONT |
> AVFMT_NO_BYTE_SEEK | AVFMT_NOGENSEARCH | AVFMT_NOBINSEARCH,
> +    .flags_internal = FF_FMT_INIT_CLEANUP,
> +    .read_close     = dvdvideo_close,
> +    .read_header    = dvdvideo_read_header,
> +    .read_packet    = dvdvideo_read_packet
> +};
> --
> 2.34.1
>
>