| Message ID | 20200418142547.21299-2-jstebbins@jetheaddev.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [FFmpeg-devel,1/4] lavc/pgs_frame_merge_bsf: add bsf to merge PGS segments | expand |
| Context | Check | Description |
|---|---|---|
| andriy/default | pending | |
| andriy/configure | warning | Failed to apply patch |
John Stebbins: > Required to remux m2ts to mkv > --- > Changelog | 1 + > doc/bitstream_filters.texi | 8 ++ > libavcodec/Makefile | 1 + > libavcodec/bitstream_filters.c | 1 + > libavcodec/pgs_frame_merge_bsf.c | 168 +++++++++++++++++++++++++++++++ > 5 files changed, 179 insertions(+) > create mode 100644 libavcodec/pgs_frame_merge_bsf.c > > diff --git a/Changelog b/Changelog > index d9fcd8bb0a..fec4867488 100644 > --- a/Changelog > +++ b/Changelog > @@ -59,6 +59,7 @@ version <next>: > - mv30 decoder > - Expanded styling support for 3GPP Timed Text Subtitles (movtext) > - WebP parser > +- PGS subtitle frame merge bitstream filter > > > version 4.2: > diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi > index 8fe5b3ad75..21ed09986c 100644 > --- a/doc/bitstream_filters.texi > +++ b/doc/bitstream_filters.texi > @@ -548,6 +548,14 @@ ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv > @section null > This bitstream filter passes the packets through unchanged. > > +@section pgs_frame_merge > + > +Merge a sequence of PGS Subtitle segments ending with an "end of display set" > +segment into a single packet. > + > +This is required by some containers that support PGS subtitles > +(muxer @code{matroska}). > + > @section prores_metadata > > Modify color property metadata embedded in prores stream. > diff --git a/libavcodec/Makefile b/libavcodec/Makefile > index 88944d9a3a..b630de21bc 100644 > --- a/libavcodec/Makefile > +++ b/libavcodec/Makefile > @@ -1115,6 +1115,7 @@ OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += mp3_header_decompress_bsf.o \ > OBJS-$(CONFIG_MPEG2_METADATA_BSF) += mpeg2_metadata_bsf.o > OBJS-$(CONFIG_NOISE_BSF) += noise_bsf.o > OBJS-$(CONFIG_NULL_BSF) += null_bsf.o > +OBJS-$(CONFIG_PGS_FRAME_MERGE_BSF) += pgs_frame_merge_bsf.o > OBJS-$(CONFIG_PRORES_METADATA_BSF) += prores_metadata_bsf.o > OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF) += remove_extradata_bsf.o > OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o > diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c > index 6b5ffe4d70..92619225f0 100644 > --- a/libavcodec/bitstream_filters.c > +++ b/libavcodec/bitstream_filters.c > @@ -49,6 +49,7 @@ extern const AVBitStreamFilter ff_mpeg4_unpack_bframes_bsf; > extern const AVBitStreamFilter ff_mov2textsub_bsf; > extern const AVBitStreamFilter ff_noise_bsf; > extern const AVBitStreamFilter ff_null_bsf; > +extern const AVBitStreamFilter ff_pgs_frame_merge_bsf; > extern const AVBitStreamFilter ff_prores_metadata_bsf; > extern const AVBitStreamFilter ff_remove_extradata_bsf; > extern const AVBitStreamFilter ff_text2movsub_bsf; > diff --git a/libavcodec/pgs_frame_merge_bsf.c b/libavcodec/pgs_frame_merge_bsf.c > new file mode 100644 > index 0000000000..cae5c75655 > --- /dev/null > +++ b/libavcodec/pgs_frame_merge_bsf.c > @@ -0,0 +1,168 @@ > +/* > + * Copyright (c) 2020 John Stebbins <jstebbins.hb@gmail.com> > + * > + * 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 > + */ > + > +/** > + * @file > + * This bitstream filter merges PGS subtitle packets containing incomplete > + * set of segments into a single packet > + * > + * Packets already containing a complete set of segments will be passed through > + * unchanged. > + */ > + > +#include "avcodec.h" > +#include "bsf.h" > +#include "libavutil/intreadwrite.h" > + > +enum PGSSegmentType { > + PALETTE_SEGMENT = 0x14, > + OBJECT_SEGMENT = 0x15, > + PRESENTATION_SEGMENT = 0x16, > + WINDOW_SEGMENT = 0x17, > + DISPLAY_SEGMENT = 0x80, > +}; > + > +typedef struct PGSMergeContext { > + AVPacket *buffer_pkt, *in; > + int presentation_found; > +} PGSMergeContext; > + > +static void frame_merge_flush(AVBSFContext *bsf) > +{ > + PGSMergeContext *ctx = bsf->priv_data; > + > + av_packet_unref(ctx->in); > + av_packet_unref(ctx->buffer_pkt); flush should reset ctx->presentation_found, shouldn't it? > +} > + > +static int frame_merge_filter(AVBSFContext *bsf, AVPacket *out) > +{ > + PGSMergeContext *ctx = bsf->priv_data; > + AVPacket *in = ctx->in, *pkt = ctx->buffer_pkt; > + int ret, i, size, pos, display = 0; > + > + if (!in->data) { > + ret = ff_bsf_get_packet_ref(bsf, in); > + if (ret < 0) > + return ret; > + } > + if (!in->size) { > + av_packet_unref(in); > + return AVERROR(EAGAIN); > + } > + > + // Validate packet data and find display_end segment > + size = in->size; > + i = 0; > + while (i + 3 <= in->size) { > + uint8_t segment_type; > + int segment_len; > + > + segment_type = in->data[i]; > + segment_len = AV_RB16(in->data + i + 1) + 3; > + if (i + segment_len > in->size) // Invalid data Possible overflow. Use an unsigned as segment_len to avoid it. > + break; > + if (segment_type == PRESENTATION_SEGMENT && i + 10 < in->size && > + !ctx->presentation_found) { > + uint8_t state; > + ctx->presentation_found = 1; > + ret = av_packet_copy_props(pkt, in); This will copy the properties even if it eventually turns out that one can just pass through the packet. Even worse: Imagine the input packet having side-data. Then pkt contains side-data, yet the code thinks that this packet is blank. This side data will then leak when the properties of the next presentation segment are copied. Furthermore, I would actually have expected the pts of the display segment to be used. Or are they guaranteed to be identical? > + if (ret < 0) > + goto fail; > + state = in->data[i + 10] & 0xc0; This amounts to the composition_state of the composition_descriptor(), doesn't it? > + if (state) > + pkt->flags |= AV_PKT_FLAG_KEY; The keyframe flag will be ignored on passthrough. Also, should the flag be cleared if state == 0? > + } > + i += segment_len; > + if (segment_type == DISPLAY_SEGMENT) { > + size = display = i; > + break; > + } > + } > + if (display && pkt->size == 0 && size == in->size) { // passthrough > + ctx->presentation_found = 0; > + av_packet_move_ref(out, in); > + return 0; > + } > + if ((!display && i != in->size) || size > in->size) { I don't see how size > in->size can ever be true. > + av_log(bsf, AV_LOG_WARNING, "Failed to parse PGS segments.\n"); > + // force output what we have > + display = size = in->size; If you output a corrupt packet, you should set the AV_PKT_FLAG_CORRUPT flag. > + } > + > + pos = pkt->size; > + ret = av_grow_packet(pkt, size); > + if (ret < 0) > + goto fail; > + memcpy(pkt->data + pos, in->data, size); > + > + if (size == in->size) > + av_packet_unref(in); > + else { > + in->data += size; > + in->size -= size; > + } > + > + if (display) { > + ctx->presentation_found = 0; I don't see anything in the code that actually enforces that a presentation segment has been found at this point; the properties of the output packet would then still be blank. Is this intended? If it is spec-incompliant, then one should add the AV_PKT_FLAG_CORRUPT flag. > + av_packet_move_ref(out, pkt); > + return 0; > + } > + return AVERROR(EAGAIN); > + > +fail: > + ctx->presentation_found = 0; > + frame_merge_flush(bsf); > + return ret; > +} > + > +static int frame_merge_init(AVBSFContext *bsf) > +{ > + PGSMergeContext *ctx = bsf->priv_data; > + > + ctx->in = av_packet_alloc(); > + ctx->buffer_pkt = av_packet_alloc(); > + if (!ctx->in || !ctx->buffer_pkt) > + return AVERROR(ENOMEM); > + > + return 0; > +} > + > +static void frame_merge_close(AVBSFContext *bsf) > +{ > + PGSMergeContext *ctx = bsf->priv_data; > + > + av_packet_free(&ctx->in); > + av_packet_free(&ctx->buffer_pkt); > +} > + > +static const enum AVCodecID frame_merge_codec_ids[] = { > + AV_CODEC_ID_HDMV_PGS_SUBTITLE, AV_CODEC_ID_NONE, > +}; > + > +const AVBitStreamFilter ff_pgs_frame_merge_bsf = { > + .name = "pgs_frame_merge", > + .priv_data_size = sizeof(PGSMergeContext), > + .init = frame_merge_init, > + .flush = frame_merge_flush, > + .close = frame_merge_close, > + .filter = frame_merge_filter, > + .codec_ids = frame_merge_codec_ids, > +}; >
John Stebbins: > Required to remux m2ts to mkv > --- > Changelog | 1 + > doc/bitstream_filters.texi | 8 ++ > libavcodec/Makefile | 1 + > libavcodec/bitstream_filters.c | 1 + > libavcodec/pgs_frame_merge_bsf.c | 168 +++++++++++++++++++++++++++++++ > 5 files changed, 179 insertions(+) > create mode 100644 libavcodec/pgs_frame_merge_bsf.c > > diff --git a/Changelog b/Changelog > index d9fcd8bb0a..fec4867488 100644 > --- a/Changelog > +++ b/Changelog > @@ -59,6 +59,7 @@ version <next>: > - mv30 decoder > - Expanded styling support for 3GPP Timed Text Subtitles (movtext) > - WebP parser > +- PGS subtitle frame merge bitstream filter > > > version 4.2: > diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi > index 8fe5b3ad75..21ed09986c 100644 > --- a/doc/bitstream_filters.texi > +++ b/doc/bitstream_filters.texi > @@ -548,6 +548,14 @@ ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv > @section null > This bitstream filter passes the packets through unchanged. > > +@section pgs_frame_merge > + > +Merge a sequence of PGS Subtitle segments ending with an "end of display set" > +segment into a single packet. > + > +This is required by some containers that support PGS subtitles > +(muxer @code{matroska}). > + > @section prores_metadata > > Modify color property metadata embedded in prores stream. > diff --git a/libavcodec/Makefile b/libavcodec/Makefile > index 88944d9a3a..b630de21bc 100644 > --- a/libavcodec/Makefile > +++ b/libavcodec/Makefile > @@ -1115,6 +1115,7 @@ OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += mp3_header_decompress_bsf.o \ > OBJS-$(CONFIG_MPEG2_METADATA_BSF) += mpeg2_metadata_bsf.o > OBJS-$(CONFIG_NOISE_BSF) += noise_bsf.o > OBJS-$(CONFIG_NULL_BSF) += null_bsf.o > +OBJS-$(CONFIG_PGS_FRAME_MERGE_BSF) += pgs_frame_merge_bsf.o > OBJS-$(CONFIG_PRORES_METADATA_BSF) += prores_metadata_bsf.o > OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF) += remove_extradata_bsf.o > OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o > diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c > index 6b5ffe4d70..92619225f0 100644 > --- a/libavcodec/bitstream_filters.c > +++ b/libavcodec/bitstream_filters.c > @@ -49,6 +49,7 @@ extern const AVBitStreamFilter ff_mpeg4_unpack_bframes_bsf; > extern const AVBitStreamFilter ff_mov2textsub_bsf; > extern const AVBitStreamFilter ff_noise_bsf; > extern const AVBitStreamFilter ff_null_bsf; > +extern const AVBitStreamFilter ff_pgs_frame_merge_bsf; > extern const AVBitStreamFilter ff_prores_metadata_bsf; > extern const AVBitStreamFilter ff_remove_extradata_bsf; > extern const AVBitStreamFilter ff_text2movsub_bsf; > diff --git a/libavcodec/pgs_frame_merge_bsf.c b/libavcodec/pgs_frame_merge_bsf.c > new file mode 100644 > index 0000000000..cae5c75655 > --- /dev/null > +++ b/libavcodec/pgs_frame_merge_bsf.c > @@ -0,0 +1,168 @@ > +/* > + * Copyright (c) 2020 John Stebbins <jstebbins.hb@gmail.com> > + * > + * 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 > + */ > + > +/** > + * @file > + * This bitstream filter merges PGS subtitle packets containing incomplete > + * set of segments into a single packet > + * > + * Packets already containing a complete set of segments will be passed through > + * unchanged. > + */ > + > +#include "avcodec.h" > +#include "bsf.h" > +#include "libavutil/intreadwrite.h" > + > +enum PGSSegmentType { > + PALETTE_SEGMENT = 0x14, > + OBJECT_SEGMENT = 0x15, > + PRESENTATION_SEGMENT = 0x16, > + WINDOW_SEGMENT = 0x17, > + DISPLAY_SEGMENT = 0x80, > +}; > + > +typedef struct PGSMergeContext { > + AVPacket *buffer_pkt, *in; > + int presentation_found; > +} PGSMergeContext; > + > +static void frame_merge_flush(AVBSFContext *bsf) > +{ > + PGSMergeContext *ctx = bsf->priv_data; > + > + av_packet_unref(ctx->in); > + av_packet_unref(ctx->buffer_pkt); > +} > + > +static int frame_merge_filter(AVBSFContext *bsf, AVPacket *out) > +{ > + PGSMergeContext *ctx = bsf->priv_data; > + AVPacket *in = ctx->in, *pkt = ctx->buffer_pkt; > + int ret, i, size, pos, display = 0; > + > + if (!in->data) { > + ret = ff_bsf_get_packet_ref(bsf, in); > + if (ret < 0) > + return ret; > + } > + if (!in->size) { > + av_packet_unref(in); > + return AVERROR(EAGAIN); > + } > + > + // Validate packet data and find display_end segment > + size = in->size; > + i = 0; > + while (i + 3 <= in->size) { > + uint8_t segment_type; > + int segment_len; > + > + segment_type = in->data[i]; > + segment_len = AV_RB16(in->data + i + 1) + 3; > + if (i + segment_len > in->size) // Invalid data > + break; > + if (segment_type == PRESENTATION_SEGMENT && i + 10 < in->size && > + !ctx->presentation_found) { > + uint8_t state; > + ctx->presentation_found = 1; > + ret = av_packet_copy_props(pkt, in); > + if (ret < 0) > + goto fail; > + state = in->data[i + 10] & 0xc0; > + if (state) > + pkt->flags |= AV_PKT_FLAG_KEY; > + } > + i += segment_len; > + if (segment_type == DISPLAY_SEGMENT) { > + size = display = i; > + break; > + } > + } > + if (display && pkt->size == 0 && size == in->size) { // passthrough > + ctx->presentation_found = 0; > + av_packet_move_ref(out, in); > + return 0; > + } > + if ((!display && i != in->size) || size > in->size) { > + av_log(bsf, AV_LOG_WARNING, "Failed to parse PGS segments.\n"); You should include libavutil/log.h because of this. > + // force output what we have > + display = size = in->size; > + } > + > + pos = pkt->size; > + ret = av_grow_packet(pkt, size); > + if (ret < 0) > + goto fail; > + memcpy(pkt->data + pos, in->data, size); > + > + if (size == in->size) > + av_packet_unref(in); > + else { > + in->data += size; > + in->size -= size; > + } > + > + if (display) { > + ctx->presentation_found = 0; > + av_packet_move_ref(out, pkt); > + return 0; > + } > + return AVERROR(EAGAIN); > + > +fail: > + ctx->presentation_found = 0; > + frame_merge_flush(bsf); > + return ret; > +} > + > +static int frame_merge_init(AVBSFContext *bsf) > +{ > + PGSMergeContext *ctx = bsf->priv_data; > + > + ctx->in = av_packet_alloc(); > + ctx->buffer_pkt = av_packet_alloc(); > + if (!ctx->in || !ctx->buffer_pkt) > + return AVERROR(ENOMEM); > + > + return 0; > +} > + > +static void frame_merge_close(AVBSFContext *bsf) > +{ > + PGSMergeContext *ctx = bsf->priv_data; > + > + av_packet_free(&ctx->in); > + av_packet_free(&ctx->buffer_pkt); > +} > + > +static const enum AVCodecID frame_merge_codec_ids[] = { > + AV_CODEC_ID_HDMV_PGS_SUBTITLE, AV_CODEC_ID_NONE, > +}; > + > +const AVBitStreamFilter ff_pgs_frame_merge_bsf = { > + .name = "pgs_frame_merge", > + .priv_data_size = sizeof(PGSMergeContext), > + .init = frame_merge_init, > + .flush = frame_merge_flush, > + .close = frame_merge_close, > + .filter = frame_merge_filter, > + .codec_ids = frame_merge_codec_ids, > +}; >
On Sat, 2020-05-02 at 22:30 +0200, Andreas Rheinhardt wrote: > John Stebbins: > > Required to remux m2ts to mkv > > --- > > Changelog | 1 + > > doc/bitstream_filters.texi | 8 ++ > > libavcodec/Makefile | 1 + > > libavcodec/bitstream_filters.c | 1 + > > libavcodec/pgs_frame_merge_bsf.c | 168 > > +++++++++++++++++++++++++++++++ > > 5 files changed, 179 insertions(+) > > create mode 100644 libavcodec/pgs_frame_merge_bsf.c > > > > diff --git a/Changelog b/Changelog > > index d9fcd8bb0a..fec4867488 100644 > > --- a/Changelog > > +++ b/Changelog > > @@ -59,6 +59,7 @@ version <next>: > > - mv30 decoder > > - Expanded styling support for 3GPP Timed Text Subtitles (movtext) > > - WebP parser > > +- PGS subtitle frame merge bitstream filter > > > > > > version 4.2: > > diff --git a/doc/bitstream_filters.texi > > b/doc/bitstream_filters.texi > > index 8fe5b3ad75..21ed09986c 100644 > > --- a/doc/bitstream_filters.texi > > +++ b/doc/bitstream_filters.texi > > @@ -548,6 +548,14 @@ ffmpeg -i INPUT -c copy -bsf noise[=1] > > output.mkv > > @section null > > This bitstream filter passes the packets through unchanged. > > > > +@section pgs_frame_merge > > + > > +Merge a sequence of PGS Subtitle segments ending with an "end of > > display set" > > +segment into a single packet. > > + > > +This is required by some containers that support PGS subtitles > > +(muxer @code{matroska}). > > + > > @section prores_metadata > > > > Modify color property metadata embedded in prores stream. > > diff --git a/libavcodec/Makefile b/libavcodec/Makefile > > index 88944d9a3a..b630de21bc 100644 > > --- a/libavcodec/Makefile > > +++ b/libavcodec/Makefile > > @@ -1115,6 +1115,7 @@ OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += > > mp3_header_decompress_bsf.o \ > > OBJS-$(CONFIG_MPEG2_METADATA_BSF) += mpeg2_metadata_bsf.o > > OBJS-$(CONFIG_NOISE_BSF) += noise_bsf.o > > OBJS-$(CONFIG_NULL_BSF) += null_bsf.o > > +OBJS-$(CONFIG_PGS_FRAME_MERGE_BSF) += pgs_frame_merge_bsf.o > > OBJS-$(CONFIG_PRORES_METADATA_BSF) += prores_metadata_bsf.o > > OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF) += > > remove_extradata_bsf.o > > OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o > > diff --git a/libavcodec/bitstream_filters.c > > b/libavcodec/bitstream_filters.c > > index 6b5ffe4d70..92619225f0 100644 > > --- a/libavcodec/bitstream_filters.c > > +++ b/libavcodec/bitstream_filters.c > > @@ -49,6 +49,7 @@ extern const AVBitStreamFilter > > ff_mpeg4_unpack_bframes_bsf; > > extern const AVBitStreamFilter ff_mov2textsub_bsf; > > extern const AVBitStreamFilter ff_noise_bsf; > > extern const AVBitStreamFilter ff_null_bsf; > > +extern const AVBitStreamFilter ff_pgs_frame_merge_bsf; > > extern const AVBitStreamFilter ff_prores_metadata_bsf; > > extern const AVBitStreamFilter ff_remove_extradata_bsf; > > extern const AVBitStreamFilter ff_text2movsub_bsf; > > diff --git a/libavcodec/pgs_frame_merge_bsf.c > > b/libavcodec/pgs_frame_merge_bsf.c > > new file mode 100644 > > index 0000000000..cae5c75655 > > --- /dev/null > > +++ b/libavcodec/pgs_frame_merge_bsf.c > > @@ -0,0 +1,168 @@ > > +/* > > + * Copyright (c) 2020 John Stebbins <jstebbins.hb@gmail.com> > > + * > > + * 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 > > + */ > > + > > +/** > > + * @file > > + * This bitstream filter merges PGS subtitle packets containing > > incomplete > > + * set of segments into a single packet > > + * > > + * Packets already containing a complete set of segments will be > > passed through > > + * unchanged. > > + */ > > + > > +#include "avcodec.h" > > +#include "bsf.h" > > +#include "libavutil/intreadwrite.h" > > + > > +enum PGSSegmentType { > > + PALETTE_SEGMENT = 0x14, > > + OBJECT_SEGMENT = 0x15, > > + PRESENTATION_SEGMENT = 0x16, > > + WINDOW_SEGMENT = 0x17, > > + DISPLAY_SEGMENT = 0x80, > > +}; > > + > > +typedef struct PGSMergeContext { > > + AVPacket *buffer_pkt, *in; > > + int presentation_found; > > +} PGSMergeContext; > > + > > +static void frame_merge_flush(AVBSFContext *bsf) > > +{ > > + PGSMergeContext *ctx = bsf->priv_data; > > + > > + av_packet_unref(ctx->in); > > + av_packet_unref(ctx->buffer_pkt); > > flush should reset ctx->presentation_found, shouldn't it? Ok > > > +} > > + > > +static int frame_merge_filter(AVBSFContext *bsf, AVPacket *out) > > +{ > > + PGSMergeContext *ctx = bsf->priv_data; > > + AVPacket *in = ctx->in, *pkt = ctx->buffer_pkt; > > + int ret, i, size, pos, display = 0; > > + > > + if (!in->data) { > > + ret = ff_bsf_get_packet_ref(bsf, in); > > + if (ret < 0) > > + return ret; > > + } > > + if (!in->size) { > > + av_packet_unref(in); > > + return AVERROR(EAGAIN); > > + } > > + > > + // Validate packet data and find display_end segment > > + size = in->size; > > + i = 0; > > + while (i + 3 <= in->size) { > > + uint8_t segment_type; > > + int segment_len; > > + > > + segment_type = in->data[i]; > > + segment_len = AV_RB16(in->data + i + 1) + 3; > > + if (i + segment_len > in->size) // Invalid data > > Possible overflow. Use an unsigned as segment_len to avoid it. Not trying to be pithy, just making sure I understand exactly what you mean. If I'm understanding right, you wish to protect against the case that in->size is > 2^31 - 2^16 and there are more than 32768 segments found and the last segment length is > 2^31 - in->size? Those are the only circumstances I see an overflow happening, so am I understanding correctly? > > > + break; > > + if (segment_type == PRESENTATION_SEGMENT && i + 10 < in- > > >size && > > + !ctx->presentation_found) { > > + uint8_t state; > > + ctx->presentation_found = 1; > > + ret = av_packet_copy_props(pkt, in); > > This will copy the properties even if it eventually turns out that > one > can just pass through the packet. Even worse: Imagine the input > packet > having side-data. Then pkt contains side-data, yet the code thinks > that > this packet is blank. This side data will then leak when the > properties > of the next presentation segment are copied. > Right, thanks. > Furthermore, I would actually have expected the pts of the display > segment to be used. Or are they guaranteed to be identical? pgssubdec gave the "end display set segment" a poor name (i'm guessing for the sake of brevity) and I've gone an propagated it :( I'll rename that enum to make it more clear. Display time is actually defined by the presentation segment's pts. > > > + if (ret < 0) > > + goto fail; > > + state = in->data[i + 10] & 0xc0; > > This amounts to the composition_state of the > composition_descriptor(), > doesn't it? Yes, it turns out any non-zero value for the composition state says this in the spec: "The Display Set contains all elements needed to display the next composition." Different non-zero states define how the "Epoch" is handled which basically defines when things come into and go out of scope. > > > + if (state) > > + pkt->flags |= AV_PKT_FLAG_KEY; > > The keyframe flag will be ignored on passthrough. Will fix > Also, should the flag > be cleared if state == 0? > Yes. Will do. > > + } > > + i += segment_len; > > + if (segment_type == DISPLAY_SEGMENT) { > > + size = display = i; > > + break; > > + } > > + } > > + if (display && pkt->size == 0 && size == in->size) { // > > passthrough > > + ctx->presentation_found = 0; > > + av_packet_move_ref(out, in); > > + return 0; > > + } > > + if ((!display && i != in->size) || size > in->size) { > > I don't see how size > in->size can ever be true. > It could in an earlier iteration. Will fix. > > + av_log(bsf, AV_LOG_WARNING, "Failed to parse PGS > > segments.\n"); > > + // force output what we have > > + display = size = in->size; > > If you output a corrupt packet, you should set the > AV_PKT_FLAG_CORRUPT flag. > OK > > + } > > + > > + pos = pkt->size; > > + ret = av_grow_packet(pkt, size); > > + if (ret < 0) > > + goto fail; > > + memcpy(pkt->data + pos, in->data, size); > > + > > + if (size == in->size) > > + av_packet_unref(in); > > + else { > > + in->data += size; > > + in->size -= size; > > + } > > + > > + if (display) { > > + ctx->presentation_found = 0; > > I don't see anything in the code that actually enforces that a > presentation segment has been found at this point; the properties of > the > output packet would then still be blank. Is this intended? If it is > spec-incompliant, then one should add the AV_PKT_FLAG_CORRUPT flag. > Good point. Will do. > > + av_packet_move_ref(out, pkt); > > + return 0; > > + } > > + return AVERROR(EAGAIN); > > + > > +fail: > > + ctx->presentation_found = 0; > > + frame_merge_flush(bsf); > > + return ret; > > +} > > + > > +static int frame_merge_init(AVBSFContext *bsf) > > +{ > > + PGSMergeContext *ctx = bsf->priv_data; > > + > > + ctx->in = av_packet_alloc(); > > + ctx->buffer_pkt = av_packet_alloc(); > > + if (!ctx->in || !ctx->buffer_pkt) > > + return AVERROR(ENOMEM); > > + > > + return 0; > > +} > > + > > +static void frame_merge_close(AVBSFContext *bsf) > > +{ > > + PGSMergeContext *ctx = bsf->priv_data; > > + > > + av_packet_free(&ctx->in); > > + av_packet_free(&ctx->buffer_pkt); > > +} > > + > > +static const enum AVCodecID frame_merge_codec_ids[] = { > > + AV_CODEC_ID_HDMV_PGS_SUBTITLE, AV_CODEC_ID_NONE, > > +}; > > + > > +const AVBitStreamFilter ff_pgs_frame_merge_bsf = { > > + .name = "pgs_frame_merge", > > + .priv_data_size = sizeof(PGSMergeContext), > > + .init = frame_merge_init, > > + .flush = frame_merge_flush, > > + .close = frame_merge_close, > > + .filter = frame_merge_filter, > > + .codec_ids = frame_merge_codec_ids, > > +}; > > > > Also, will add av_log header you comment on in your next email.
John Stebbins: > On Sat, 2020-05-02 at 22:30 +0200, Andreas Rheinhardt wrote: >> John Stebbins: >>> Required to remux m2ts to mkv >>> --- >>> Changelog | 1 + >>> doc/bitstream_filters.texi | 8 ++ >>> libavcodec/Makefile | 1 + >>> libavcodec/bitstream_filters.c | 1 + >>> libavcodec/pgs_frame_merge_bsf.c | 168 >>> +++++++++++++++++++++++++++++++ >>> 5 files changed, 179 insertions(+) >>> create mode 100644 libavcodec/pgs_frame_merge_bsf.c >>> >>> diff --git a/Changelog b/Changelog >>> index d9fcd8bb0a..fec4867488 100644 >>> --- a/Changelog >>> +++ b/Changelog >>> @@ -59,6 +59,7 @@ version <next>: >>> - mv30 decoder >>> - Expanded styling support for 3GPP Timed Text Subtitles (movtext) >>> - WebP parser >>> +- PGS subtitle frame merge bitstream filter >>> >>> >>> version 4.2: >>> diff --git a/doc/bitstream_filters.texi >>> b/doc/bitstream_filters.texi >>> index 8fe5b3ad75..21ed09986c 100644 >>> --- a/doc/bitstream_filters.texi >>> +++ b/doc/bitstream_filters.texi >>> @@ -548,6 +548,14 @@ ffmpeg -i INPUT -c copy -bsf noise[=1] >>> output.mkv >>> @section null >>> This bitstream filter passes the packets through unchanged. >>> >>> +@section pgs_frame_merge >>> + >>> +Merge a sequence of PGS Subtitle segments ending with an "end of >>> display set" >>> +segment into a single packet. >>> + >>> +This is required by some containers that support PGS subtitles >>> +(muxer @code{matroska}). >>> + >>> @section prores_metadata >>> >>> Modify color property metadata embedded in prores stream. >>> diff --git a/libavcodec/Makefile b/libavcodec/Makefile >>> index 88944d9a3a..b630de21bc 100644 >>> --- a/libavcodec/Makefile >>> +++ b/libavcodec/Makefile >>> @@ -1115,6 +1115,7 @@ OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += >>> mp3_header_decompress_bsf.o \ >>> OBJS-$(CONFIG_MPEG2_METADATA_BSF) += mpeg2_metadata_bsf.o >>> OBJS-$(CONFIG_NOISE_BSF) += noise_bsf.o >>> OBJS-$(CONFIG_NULL_BSF) += null_bsf.o >>> +OBJS-$(CONFIG_PGS_FRAME_MERGE_BSF) += pgs_frame_merge_bsf.o >>> OBJS-$(CONFIG_PRORES_METADATA_BSF) += prores_metadata_bsf.o >>> OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF) += >>> remove_extradata_bsf.o >>> OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o >>> diff --git a/libavcodec/bitstream_filters.c >>> b/libavcodec/bitstream_filters.c >>> index 6b5ffe4d70..92619225f0 100644 >>> --- a/libavcodec/bitstream_filters.c >>> +++ b/libavcodec/bitstream_filters.c >>> @@ -49,6 +49,7 @@ extern const AVBitStreamFilter >>> ff_mpeg4_unpack_bframes_bsf; >>> extern const AVBitStreamFilter ff_mov2textsub_bsf; >>> extern const AVBitStreamFilter ff_noise_bsf; >>> extern const AVBitStreamFilter ff_null_bsf; >>> +extern const AVBitStreamFilter ff_pgs_frame_merge_bsf; >>> extern const AVBitStreamFilter ff_prores_metadata_bsf; >>> extern const AVBitStreamFilter ff_remove_extradata_bsf; >>> extern const AVBitStreamFilter ff_text2movsub_bsf; >>> diff --git a/libavcodec/pgs_frame_merge_bsf.c >>> b/libavcodec/pgs_frame_merge_bsf.c >>> new file mode 100644 >>> index 0000000000..cae5c75655 >>> --- /dev/null >>> +++ b/libavcodec/pgs_frame_merge_bsf.c >>> @@ -0,0 +1,168 @@ >>> +/* >>> + * Copyright (c) 2020 John Stebbins <jstebbins.hb@gmail.com> >>> + * >>> + * 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 >>> + */ >>> + >>> +/** >>> + * @file >>> + * This bitstream filter merges PGS subtitle packets containing >>> incomplete >>> + * set of segments into a single packet >>> + * >>> + * Packets already containing a complete set of segments will be >>> passed through >>> + * unchanged. >>> + */ >>> + >>> +#include "avcodec.h" >>> +#include "bsf.h" >>> +#include "libavutil/intreadwrite.h" >>> + >>> +enum PGSSegmentType { >>> + PALETTE_SEGMENT = 0x14, >>> + OBJECT_SEGMENT = 0x15, >>> + PRESENTATION_SEGMENT = 0x16, >>> + WINDOW_SEGMENT = 0x17, >>> + DISPLAY_SEGMENT = 0x80, >>> +}; >>> + >>> +typedef struct PGSMergeContext { >>> + AVPacket *buffer_pkt, *in; >>> + int presentation_found; >>> +} PGSMergeContext; >>> + >>> +static void frame_merge_flush(AVBSFContext *bsf) >>> +{ >>> + PGSMergeContext *ctx = bsf->priv_data; >>> + >>> + av_packet_unref(ctx->in); >>> + av_packet_unref(ctx->buffer_pkt); >> >> flush should reset ctx->presentation_found, shouldn't it? > > Ok > >> >>> +} >>> + >>> +static int frame_merge_filter(AVBSFContext *bsf, AVPacket *out) >>> +{ >>> + PGSMergeContext *ctx = bsf->priv_data; >>> + AVPacket *in = ctx->in, *pkt = ctx->buffer_pkt; >>> + int ret, i, size, pos, display = 0; >>> + >>> + if (!in->data) { >>> + ret = ff_bsf_get_packet_ref(bsf, in); >>> + if (ret < 0) >>> + return ret; >>> + } >>> + if (!in->size) { >>> + av_packet_unref(in); >>> + return AVERROR(EAGAIN); >>> + } >>> + >>> + // Validate packet data and find display_end segment >>> + size = in->size; >>> + i = 0; >>> + while (i + 3 <= in->size) { >>> + uint8_t segment_type; >>> + int segment_len; >>> + >>> + segment_type = in->data[i]; >>> + segment_len = AV_RB16(in->data + i + 1) + 3; >>> + if (i + segment_len > in->size) // Invalid data >> >> Possible overflow. Use an unsigned as segment_len to avoid it. > > Not trying to be pithy, just making sure I understand exactly what you > mean. > > If I'm understanding right, you wish to protect against the case that > in->size is > 2^31 - 2^16 and there are more than 32768 segments found > and the last segment length is > 2^31 - in->size? > > Those are the only circumstances I see an overflow happening, so am I > understanding correctly? > Yes, this can happen if in->size is > INT_MAX - (2^16 + 3). The loop condition could also be changed to i <= in->size - 3. - Andreas
On Mon, 2020-05-04 at 08:29 +0200, Andreas Rheinhardt wrote: > John Stebbins: > > On Sat, 2020-05-02 at 22:30 +0200, Andreas Rheinhardt wrote: > > > John Stebbins: > > > > Required to remux m2ts to mkv > > > > --- > > > > Changelog | 1 + > > > > doc/bitstream_filters.texi | 8 ++ > > > > libavcodec/Makefile | 1 + > > > > libavcodec/bitstream_filters.c | 1 + > > > > libavcodec/pgs_frame_merge_bsf.c | 168 > > > > +++++++++++++++++++++++++++++++ > > > > 5 files changed, 179 insertions(+) > > > > create mode 100644 libavcodec/pgs_frame_merge_bsf.c > > > > > > > > diff --git a/Changelog b/Changelog > > > > index d9fcd8bb0a..fec4867488 100644 > > > > --- a/Changelog > > > > +++ b/Changelog > > > > @@ -59,6 +59,7 @@ version <next>: > > > > - mv30 decoder > > > > - Expanded styling support for 3GPP Timed Text Subtitles > > > > (movtext) > > > > - WebP parser > > > > +- PGS subtitle frame merge bitstream filter > > > > > > > > > > > > version 4.2: > > > > diff --git a/doc/bitstream_filters.texi > > > > b/doc/bitstream_filters.texi > > > > index 8fe5b3ad75..21ed09986c 100644 > > > > --- a/doc/bitstream_filters.texi > > > > +++ b/doc/bitstream_filters.texi > > > > @@ -548,6 +548,14 @@ ffmpeg -i INPUT -c copy -bsf noise[=1] > > > > output.mkv > > > > @section null > > > > This bitstream filter passes the packets through unchanged. > > > > > > > > +@section pgs_frame_merge > > > > + > > > > +Merge a sequence of PGS Subtitle segments ending with an "end > > > > of > > > > display set" > > > > +segment into a single packet. > > > > + > > > > +This is required by some containers that support PGS subtitles > > > > +(muxer @code{matroska}). > > > > + > > > > @section prores_metadata > > > > > > > > Modify color property metadata embedded in prores stream. > > > > diff --git a/libavcodec/Makefile b/libavcodec/Makefile > > > > index 88944d9a3a..b630de21bc 100644 > > > > --- a/libavcodec/Makefile > > > > +++ b/libavcodec/Makefile > > > > @@ -1115,6 +1115,7 @@ OBJS- > > > > $(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += > > > > mp3_header_decompress_bsf.o \ > > > > OBJS-$(CONFIG_MPEG2_METADATA_BSF) += > > > > mpeg2_metadata_bsf.o > > > > OBJS-$(CONFIG_NOISE_BSF) += noise_bsf.o > > > > OBJS-$(CONFIG_NULL_BSF) += null_bsf.o > > > > +OBJS-$(CONFIG_PGS_FRAME_MERGE_BSF) += > > > > pgs_frame_merge_bsf.o > > > > OBJS-$(CONFIG_PRORES_METADATA_BSF) += > > > > prores_metadata_bsf.o > > > > OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF) += > > > > remove_extradata_bsf.o > > > > OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o > > > > diff --git a/libavcodec/bitstream_filters.c > > > > b/libavcodec/bitstream_filters.c > > > > index 6b5ffe4d70..92619225f0 100644 > > > > --- a/libavcodec/bitstream_filters.c > > > > +++ b/libavcodec/bitstream_filters.c > > > > @@ -49,6 +49,7 @@ extern const AVBitStreamFilter > > > > ff_mpeg4_unpack_bframes_bsf; > > > > extern const AVBitStreamFilter ff_mov2textsub_bsf; > > > > extern const AVBitStreamFilter ff_noise_bsf; > > > > extern const AVBitStreamFilter ff_null_bsf; > > > > +extern const AVBitStreamFilter ff_pgs_frame_merge_bsf; > > > > extern const AVBitStreamFilter ff_prores_metadata_bsf; > > > > extern const AVBitStreamFilter ff_remove_extradata_bsf; > > > > extern const AVBitStreamFilter ff_text2movsub_bsf; > > > > diff --git a/libavcodec/pgs_frame_merge_bsf.c > > > > b/libavcodec/pgs_frame_merge_bsf.c > > > > new file mode 100644 > > > > index 0000000000..cae5c75655 > > > > --- /dev/null > > > > +++ b/libavcodec/pgs_frame_merge_bsf.c > > > > @@ -0,0 +1,168 @@ > > > > +/* > > > > + * Copyright (c) 2020 John Stebbins <jstebbins.hb@gmail.com> > > > > + * > > > > + * 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 > > > > + */ > > > > + > > > > +/** > > > > + * @file > > > > + * This bitstream filter merges PGS subtitle packets > > > > containing > > > > incomplete > > > > + * set of segments into a single packet > > > > + * > > > > + * Packets already containing a complete set of segments will > > > > be > > > > passed through > > > > + * unchanged. > > > > + */ > > > > + > > > > +#include "avcodec.h" > > > > +#include "bsf.h" > > > > +#include "libavutil/intreadwrite.h" > > > > + > > > > +enum PGSSegmentType { > > > > + PALETTE_SEGMENT = 0x14, > > > > + OBJECT_SEGMENT = 0x15, > > > > + PRESENTATION_SEGMENT = 0x16, > > > > + WINDOW_SEGMENT = 0x17, > > > > + DISPLAY_SEGMENT = 0x80, > > > > +}; > > > > + > > > > +typedef struct PGSMergeContext { > > > > + AVPacket *buffer_pkt, *in; > > > > + int presentation_found; > > > > +} PGSMergeContext; > > > > + > > > > +static void frame_merge_flush(AVBSFContext *bsf) > > > > +{ > > > > + PGSMergeContext *ctx = bsf->priv_data; > > > > + > > > > + av_packet_unref(ctx->in); > > > > + av_packet_unref(ctx->buffer_pkt); > > > > > > flush should reset ctx->presentation_found, shouldn't it? > > > > Ok > > > > > > +} > > > > + > > > > +static int frame_merge_filter(AVBSFContext *bsf, AVPacket > > > > *out) > > > > +{ > > > > + PGSMergeContext *ctx = bsf->priv_data; > > > > + AVPacket *in = ctx->in, *pkt = ctx->buffer_pkt; > > > > + int ret, i, size, pos, display = 0; > > > > + > > > > + if (!in->data) { > > > > + ret = ff_bsf_get_packet_ref(bsf, in); > > > > + if (ret < 0) > > > > + return ret; > > > > + } > > > > + if (!in->size) { > > > > + av_packet_unref(in); > > > > + return AVERROR(EAGAIN); > > > > + } > > > > + > > > > + // Validate packet data and find display_end segment > > > > + size = in->size; > > > > + i = 0; > > > > + while (i + 3 <= in->size) { > > > > + uint8_t segment_type; > > > > + int segment_len; > > > > + > > > > + segment_type = in->data[i]; > > > > + segment_len = AV_RB16(in->data + i + 1) + 3; > > > > + if (i + segment_len > in->size) // Invalid data > > > > > > Possible overflow. Use an unsigned as segment_len to avoid it. > > > > Not trying to be pithy, just making sure I understand exactly what > > you > > mean. > > > > If I'm understanding right, you wish to protect against the case > > that > > in->size is > 2^31 - 2^16 and there are more than 32768 segments > > found > > and the last segment length is > 2^31 - in->size? > > > > Those are the only circumstances I see an overflow happening, so am > > I > > understanding correctly? > > > Yes, this can happen if in->size is > INT_MAX - (2^16 + 3). > The loop condition could also be changed to i <= in->size - 3. > Thanks. I would also have to similarly modify the test inside the loop if (i + segment_len > in->size) => if (i > in->size - segment_len) I think the code reads better if I just make i unsigned. And this works as well for pgs_frame_split_bsf.
diff --git a/Changelog b/Changelog index d9fcd8bb0a..fec4867488 100644 --- a/Changelog +++ b/Changelog @@ -59,6 +59,7 @@ version <next>: - mv30 decoder - Expanded styling support for 3GPP Timed Text Subtitles (movtext) - WebP parser +- PGS subtitle frame merge bitstream filter version 4.2: diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi index 8fe5b3ad75..21ed09986c 100644 --- a/doc/bitstream_filters.texi +++ b/doc/bitstream_filters.texi @@ -548,6 +548,14 @@ ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv @section null This bitstream filter passes the packets through unchanged. +@section pgs_frame_merge + +Merge a sequence of PGS Subtitle segments ending with an "end of display set" +segment into a single packet. + +This is required by some containers that support PGS subtitles +(muxer @code{matroska}). + @section prores_metadata Modify color property metadata embedded in prores stream. diff --git a/libavcodec/Makefile b/libavcodec/Makefile index 88944d9a3a..b630de21bc 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -1115,6 +1115,7 @@ OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += mp3_header_decompress_bsf.o \ OBJS-$(CONFIG_MPEG2_METADATA_BSF) += mpeg2_metadata_bsf.o OBJS-$(CONFIG_NOISE_BSF) += noise_bsf.o OBJS-$(CONFIG_NULL_BSF) += null_bsf.o +OBJS-$(CONFIG_PGS_FRAME_MERGE_BSF) += pgs_frame_merge_bsf.o OBJS-$(CONFIG_PRORES_METADATA_BSF) += prores_metadata_bsf.o OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF) += remove_extradata_bsf.o OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c index 6b5ffe4d70..92619225f0 100644 --- a/libavcodec/bitstream_filters.c +++ b/libavcodec/bitstream_filters.c @@ -49,6 +49,7 @@ extern const AVBitStreamFilter ff_mpeg4_unpack_bframes_bsf; extern const AVBitStreamFilter ff_mov2textsub_bsf; extern const AVBitStreamFilter ff_noise_bsf; extern const AVBitStreamFilter ff_null_bsf; +extern const AVBitStreamFilter ff_pgs_frame_merge_bsf; extern const AVBitStreamFilter ff_prores_metadata_bsf; extern const AVBitStreamFilter ff_remove_extradata_bsf; extern const AVBitStreamFilter ff_text2movsub_bsf; diff --git a/libavcodec/pgs_frame_merge_bsf.c b/libavcodec/pgs_frame_merge_bsf.c new file mode 100644 index 0000000000..cae5c75655 --- /dev/null +++ b/libavcodec/pgs_frame_merge_bsf.c @@ -0,0 +1,168 @@ +/* + * Copyright (c) 2020 John Stebbins <jstebbins.hb@gmail.com> + * + * 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 + */ + +/** + * @file + * This bitstream filter merges PGS subtitle packets containing incomplete + * set of segments into a single packet + * + * Packets already containing a complete set of segments will be passed through + * unchanged. + */ + +#include "avcodec.h" +#include "bsf.h" +#include "libavutil/intreadwrite.h" + +enum PGSSegmentType { + PALETTE_SEGMENT = 0x14, + OBJECT_SEGMENT = 0x15, + PRESENTATION_SEGMENT = 0x16, + WINDOW_SEGMENT = 0x17, + DISPLAY_SEGMENT = 0x80, +}; + +typedef struct PGSMergeContext { + AVPacket *buffer_pkt, *in; + int presentation_found; +} PGSMergeContext; + +static void frame_merge_flush(AVBSFContext *bsf) +{ + PGSMergeContext *ctx = bsf->priv_data; + + av_packet_unref(ctx->in); + av_packet_unref(ctx->buffer_pkt); +} + +static int frame_merge_filter(AVBSFContext *bsf, AVPacket *out) +{ + PGSMergeContext *ctx = bsf->priv_data; + AVPacket *in = ctx->in, *pkt = ctx->buffer_pkt; + int ret, i, size, pos, display = 0; + + if (!in->data) { + ret = ff_bsf_get_packet_ref(bsf, in); + if (ret < 0) + return ret; + } + if (!in->size) { + av_packet_unref(in); + return AVERROR(EAGAIN); + } + + // Validate packet data and find display_end segment + size = in->size; + i = 0; + while (i + 3 <= in->size) { + uint8_t segment_type; + int segment_len; + + segment_type = in->data[i]; + segment_len = AV_RB16(in->data + i + 1) + 3; + if (i + segment_len > in->size) // Invalid data + break; + if (segment_type == PRESENTATION_SEGMENT && i + 10 < in->size && + !ctx->presentation_found) { + uint8_t state; + ctx->presentation_found = 1; + ret = av_packet_copy_props(pkt, in); + if (ret < 0) + goto fail; + state = in->data[i + 10] & 0xc0; + if (state) + pkt->flags |= AV_PKT_FLAG_KEY; + } + i += segment_len; + if (segment_type == DISPLAY_SEGMENT) { + size = display = i; + break; + } + } + if (display && pkt->size == 0 && size == in->size) { // passthrough + ctx->presentation_found = 0; + av_packet_move_ref(out, in); + return 0; + } + if ((!display && i != in->size) || size > in->size) { + av_log(bsf, AV_LOG_WARNING, "Failed to parse PGS segments.\n"); + // force output what we have + display = size = in->size; + } + + pos = pkt->size; + ret = av_grow_packet(pkt, size); + if (ret < 0) + goto fail; + memcpy(pkt->data + pos, in->data, size); + + if (size == in->size) + av_packet_unref(in); + else { + in->data += size; + in->size -= size; + } + + if (display) { + ctx->presentation_found = 0; + av_packet_move_ref(out, pkt); + return 0; + } + return AVERROR(EAGAIN); + +fail: + ctx->presentation_found = 0; + frame_merge_flush(bsf); + return ret; +} + +static int frame_merge_init(AVBSFContext *bsf) +{ + PGSMergeContext *ctx = bsf->priv_data; + + ctx->in = av_packet_alloc(); + ctx->buffer_pkt = av_packet_alloc(); + if (!ctx->in || !ctx->buffer_pkt) + return AVERROR(ENOMEM); + + return 0; +} + +static void frame_merge_close(AVBSFContext *bsf) +{ + PGSMergeContext *ctx = bsf->priv_data; + + av_packet_free(&ctx->in); + av_packet_free(&ctx->buffer_pkt); +} + +static const enum AVCodecID frame_merge_codec_ids[] = { + AV_CODEC_ID_HDMV_PGS_SUBTITLE, AV_CODEC_ID_NONE, +}; + +const AVBitStreamFilter ff_pgs_frame_merge_bsf = { + .name = "pgs_frame_merge", + .priv_data_size = sizeof(PGSMergeContext), + .init = frame_merge_init, + .flush = frame_merge_flush, + .close = frame_merge_close, + .filter = frame_merge_filter, + .codec_ids = frame_merge_codec_ids, +};