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[FFmpeg-devel,v2] avformat/mpegtsenc: support DVB 6A descriptor for AC-3

Message ID 1597501658-27467-1-git-send-email-lance.lmwang@gmail.com
State Accepted
Headers show
Series [FFmpeg-devel,v2] avformat/mpegtsenc: support DVB 6A descriptor for AC-3 | expand

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Commit Message

Limin Wang Aug. 15, 2020, 2:27 p.m. UTC
From: Limin Wang <lance.lmwang@gmail.com>

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
---
 configure               |  2 +-
 libavformat/mpegts.h    | 16 ++++++++++
 libavformat/mpegtsenc.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 99 insertions(+), 3 deletions(-)

Comments

Guangxin Xu Aug. 15, 2020, 3:38 p.m. UTC | #1
On Sat, Aug 15, 2020 at 10:28 PM <lance.lmwang@gmail.com> wrote:

> From: Limin Wang <lance.lmwang@gmail.com>
>
> Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> ---
>  configure               |  2 +-
>  libavformat/mpegts.h    | 16 ++++++++++
>  libavformat/mpegtsenc.c | 84
> +++++++++++++++++++++++++++++++++++++++++++++++--
>  3 files changed, 99 insertions(+), 3 deletions(-)
>
> diff --git a/configure b/configure
> index d4a1fea..a9d87b2 100755
> --- a/configure
> +++ b/configure
> @@ -3324,7 +3324,7 @@ mp3_demuxer_select="mpegaudio_parser"
>  mp3_muxer_select="mpegaudioheader"
>  mp4_muxer_select="mov_muxer"
>  mpegts_demuxer_select="iso_media"
> -mpegts_muxer_select="adts_muxer latm_muxer h264_mp4toannexb_bsf
> hevc_mp4toannexb_bsf"
> +mpegts_muxer_select="ac3_parser adts_muxer latm_muxer
> h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
>  mpegtsraw_demuxer_select="mpegts_demuxer"
>  mxf_muxer_select="golomb pcm_rechunk_bsf"
>  mxf_d10_muxer_select="mxf_muxer"
> diff --git a/libavformat/mpegts.h b/libavformat/mpegts.h
> index fe10b38..d70b25d 100644
> --- a/libavformat/mpegts.h
> +++ b/libavformat/mpegts.h
> @@ -175,6 +175,22 @@ typedef struct Mp4Descr {
>      SLConfigDescr sl;
>  } Mp4Descr;
>
> +/*
> + * ETSI 300 468 descriptor 0x6A(AC-3)
> + * Refer to: ETSI EN 300 468 V1.11.1 (2010-04) (SI in DVB systems)
> + */
> +typedef struct DVBAC3Descriptor {
> +    uint8_t  component_type_flag;
> +    uint8_t  bsid_flag;
> +    uint8_t  mainid_flag;
> +    uint8_t  asvc_flag;
> +    uint8_t  reserved_flags;
> +    uint8_t  component_type;
> +    uint8_t  bsid;
> +    uint8_t  mainid;
> +    uint8_t  asvc;
> +} DVBAC3Descriptor;
> +
>  /**
>   * Parse an MPEG-2 descriptor
>   * @param[in] fc                    Format context (used for logging only)
> diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
> index 718ddab..876ba99 100644
> --- a/libavformat/mpegtsenc.c
> +++ b/libavformat/mpegtsenc.c
> @@ -27,6 +27,7 @@
>  #include "libavutil/mathematics.h"
>  #include "libavutil/opt.h"
>
> +#include "libavcodec/ac3_parser_internal.h"
>  #include "libavcodec/internal.h"
>
>  #include "avformat.h"
> @@ -244,6 +245,8 @@ typedef struct MpegTSWriteStream {
>      /* For Opus */
>      int opus_queued_samples;
>      int opus_pending_trim_start;
> +
> +    DVBAC3Descriptor *dvb_ac3_desc;
>  } MpegTSWriteStream;
>
>  static void mpegts_write_pat(AVFormatContext *s)
> @@ -486,9 +489,28 @@ static int mpegts_write_pmt(AVFormatContext *s,
> MpegTSService *service)
>          case AVMEDIA_TYPE_AUDIO:
>              if (ts->flags & MPEGTS_FLAG_SYSTEM_B) {
>                  if (codec_id == AV_CODEC_ID_AC3) {
> +                    DVBAC3Descriptor *dvb_ac3_desc = ts_st->dvb_ac3_desc;
>
need check   ts_st->dvb_ac3_desc?


+
>                      *q++=0x6a; // AC3 descriptor see A038 DVB SI
> -                    *q++=1; // 1 byte, all flags sets to 0
> -                    *q++=0; // omit all fields...
> +                    if (dvb_ac3_desc) {
> +                        int len = 1 +
> +                                  !!(dvb_ac3_desc->component_type_flag) +
> +                                  !!(dvb_ac3_desc->bsid_flag) +
> +                                  !!(dvb_ac3_desc->mainid_flag) +
> +                                  !!(dvb_ac3_desc->asvc_flag);
> +
> +                        *q++ = len;
> +                        *q++ = dvb_ac3_desc->component_type_flag << 7 |
> dvb_ac3_desc->bsid_flag << 6 |
> +                               dvb_ac3_desc->mainid_flag         << 5 |
> dvb_ac3_desc->asvc_flag << 4;
> +
> +                        if (dvb_ac3_desc->component_type_flag) *q++ =
> dvb_ac3_desc->component_type;
> +                        if (dvb_ac3_desc->bsid_flag)           *q++ =
> dvb_ac3_desc->bsid;
> +                        if (dvb_ac3_desc->mainid_flag)         *q++ =
> dvb_ac3_desc->mainid;
> +                        if (dvb_ac3_desc->asvc_flag)           *q++ =
> dvb_ac3_desc->asvc;
> +                    } else {
> +                        *q++=1; // 1 byte, all flags sets to 0
> +                        *q++=0; // omit all fields...
> +                    }
>                  } else if (codec_id == AV_CODEC_ID_EAC3) {
>                      *q++=0x7a; // EAC3 descriptor see A038 DVB SI
>                      *q++=1; // 1 byte, all flags sets to 0
> @@ -1843,6 +1865,63 @@ static int
> mpegts_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
>               * need to count the samples of that too! */
>              av_log(s, AV_LOG_WARNING, "Got MPEG-TS formatted Opus data,
> unhandled");
>          }
> +    } else if (st->codecpar->codec_id == AV_CODEC_ID_AC3 &&
> !ts_st->dvb_ac3_desc) {
> +         AC3HeaderInfo *hdr = NULL;
> +
> +        if (avpriv_ac3_parse_header(&hdr, pkt->data, pkt->size) >= 0) {
> +            uint8_t number_of_channels_flag;
> +            uint8_t service_type_flag;
> +            uint8_t full_service_flag = 1;
> +            DVBAC3Descriptor *dvb_ac3_desc;
> +
> +            dvb_ac3_desc = av_mallocz(sizeof(*dvb_ac3_desc));
> +            if (!dvb_ac3_desc) {
> +                av_free(hdr);
> +                return AVERROR(ENOMEM);
> +            }
> +
> +            service_type_flag = hdr->bitstream_mode;
> +            switch (hdr->channel_mode) {
> +                case AC3_CHMODE_DUALMONO:
> +                    number_of_channels_flag = 1;
> +                    break;
> +                case AC3_CHMODE_MONO:
> +                    number_of_channels_flag = 0;
> +                    break;
> +                case AC3_CHMODE_STEREO:
> +                    if (hdr->dolby_surround_mode == AC3_DSURMOD_ON)
> +                        number_of_channels_flag = 3;
> +                    else
> +                        number_of_channels_flag = 2;
> +                    break;
> +                case AC3_CHMODE_3F:
> +                case AC3_CHMODE_2F1R:
> +                case AC3_CHMODE_3F1R:
> +                case AC3_CHMODE_2F2R:
> +                case AC3_CHMODE_3F2R:
> +                    number_of_channels_flag = 4;
> +                    break;
> +                default: /* reserved */
> +                    number_of_channels_flag = 7;
> +                    break;
> +            }
> +
> +            if (service_type_flag  == 1 || service_type_flag == 4 ||
> +                (service_type_flag == 7 && !number_of_channels_flag))
> +                full_service_flag = 0;
> +
> +            dvb_ac3_desc->component_type_flag = 1;
> +            dvb_ac3_desc->component_type = (full_service_flag << 6)
>   |
> +                                     ((service_type_flag      & 0x7) <<
> 3) |
> +                                     (number_of_channels_flag & 0x7);
> +            dvb_ac3_desc->bsid_flag   = 1;
> +            dvb_ac3_desc->bsid        = hdr->bitstream_id;
> +            dvb_ac3_desc->mainid_flag = 0;
> +            dvb_ac3_desc->asvc_flag   = 0;
> +
> +            ts_st->dvb_ac3_desc = dvb_ac3_desc;
> +        }
> +        av_free(hdr);
>      }
>
>      if (ts_st->payload_size && (ts_st->payload_size + size >
> ts->pes_payload_size ||
> @@ -1934,6 +2013,7 @@ static void mpegts_deinit(AVFormatContext *s)
>          AVStream *st = s->streams[i];
>          MpegTSWriteStream *ts_st = st->priv_data;
>          if (ts_st) {
> +            av_freep(&ts_st->dvb_ac3_desc);
>              av_freep(&ts_st->payload);
>              if (ts_st->amux) {
>                  avformat_free_context(ts_st->amux);
> --
> 1.8.3.1
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
Limin Wang Aug. 16, 2020, 12:07 a.m. UTC | #2
On Sat, Aug 15, 2020 at 11:38:29PM +0800, Guangxin Xu wrote:
> On Sat, Aug 15, 2020 at 10:28 PM <lance.lmwang@gmail.com> wrote:
> 
> > From: Limin Wang <lance.lmwang@gmail.com>
> >
> > Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> > ---
> >  configure               |  2 +-
> >  libavformat/mpegts.h    | 16 ++++++++++
> >  libavformat/mpegtsenc.c | 84
> > +++++++++++++++++++++++++++++++++++++++++++++++--
> >  3 files changed, 99 insertions(+), 3 deletions(-)
> >
> > diff --git a/configure b/configure
> > index d4a1fea..a9d87b2 100755
> > --- a/configure
> > +++ b/configure
> > @@ -3324,7 +3324,7 @@ mp3_demuxer_select="mpegaudio_parser"
> >  mp3_muxer_select="mpegaudioheader"
> >  mp4_muxer_select="mov_muxer"
> >  mpegts_demuxer_select="iso_media"
> > -mpegts_muxer_select="adts_muxer latm_muxer h264_mp4toannexb_bsf
> > hevc_mp4toannexb_bsf"
> > +mpegts_muxer_select="ac3_parser adts_muxer latm_muxer
> > h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
> >  mpegtsraw_demuxer_select="mpegts_demuxer"
> >  mxf_muxer_select="golomb pcm_rechunk_bsf"
> >  mxf_d10_muxer_select="mxf_muxer"
> > diff --git a/libavformat/mpegts.h b/libavformat/mpegts.h
> > index fe10b38..d70b25d 100644
> > --- a/libavformat/mpegts.h
> > +++ b/libavformat/mpegts.h
> > @@ -175,6 +175,22 @@ typedef struct Mp4Descr {
> >      SLConfigDescr sl;
> >  } Mp4Descr;
> >
> > +/*
> > + * ETSI 300 468 descriptor 0x6A(AC-3)
> > + * Refer to: ETSI EN 300 468 V1.11.1 (2010-04) (SI in DVB systems)
> > + */
> > +typedef struct DVBAC3Descriptor {
> > +    uint8_t  component_type_flag;
> > +    uint8_t  bsid_flag;
> > +    uint8_t  mainid_flag;
> > +    uint8_t  asvc_flag;
> > +    uint8_t  reserved_flags;
> > +    uint8_t  component_type;
> > +    uint8_t  bsid;
> > +    uint8_t  mainid;
> > +    uint8_t  asvc;
> > +} DVBAC3Descriptor;
> > +
> >  /**
> >   * Parse an MPEG-2 descriptor
> >   * @param[in] fc                    Format context (used for logging only)
> > diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
> > index 718ddab..876ba99 100644
> > --- a/libavformat/mpegtsenc.c
> > +++ b/libavformat/mpegtsenc.c
> > @@ -27,6 +27,7 @@
> >  #include "libavutil/mathematics.h"
> >  #include "libavutil/opt.h"
> >
> > +#include "libavcodec/ac3_parser_internal.h"
> >  #include "libavcodec/internal.h"
> >
> >  #include "avformat.h"
> > @@ -244,6 +245,8 @@ typedef struct MpegTSWriteStream {
> >      /* For Opus */
> >      int opus_queued_samples;
> >      int opus_pending_trim_start;
> > +
> > +    DVBAC3Descriptor *dvb_ac3_desc;
> >  } MpegTSWriteStream;
> >
> >  static void mpegts_write_pat(AVFormatContext *s)
> > @@ -486,9 +489,28 @@ static int mpegts_write_pmt(AVFormatContext *s,
> > MpegTSService *service)
> >          case AVMEDIA_TYPE_AUDIO:
> >              if (ts->flags & MPEGTS_FLAG_SYSTEM_B) {
> >                  if (codec_id == AV_CODEC_ID_AC3) {
> > +                    DVBAC3Descriptor *dvb_ac3_desc = ts_st->dvb_ac3_desc;
> >
> need check   ts_st->dvb_ac3_desc?

Yes, the folloing code will check dvb_ac3_desc, if it's NULL, use the old default.

> 
> 
> +
> >                      *q++=0x6a; // AC3 descriptor see A038 DVB SI
> > -                    *q++=1; // 1 byte, all flags sets to 0
> > -                    *q++=0; // omit all fields...
> > +                    if (dvb_ac3_desc) {
> > +                        int len = 1 +
> > +                                  !!(dvb_ac3_desc->component_type_flag) +
> > +                                  !!(dvb_ac3_desc->bsid_flag) +
> > +                                  !!(dvb_ac3_desc->mainid_flag) +
> > +                                  !!(dvb_ac3_desc->asvc_flag);
> > +
> > +                        *q++ = len;
> > +                        *q++ = dvb_ac3_desc->component_type_flag << 7 |
> > dvb_ac3_desc->bsid_flag << 6 |
> > +                               dvb_ac3_desc->mainid_flag         << 5 |
> > dvb_ac3_desc->asvc_flag << 4;
> > +
> > +                        if (dvb_ac3_desc->component_type_flag) *q++ =
> > dvb_ac3_desc->component_type;
> > +                        if (dvb_ac3_desc->bsid_flag)           *q++ =
> > dvb_ac3_desc->bsid;
> > +                        if (dvb_ac3_desc->mainid_flag)         *q++ =
> > dvb_ac3_desc->mainid;
> > +                        if (dvb_ac3_desc->asvc_flag)           *q++ =
> > dvb_ac3_desc->asvc;
> > +                    } else {
> > +                        *q++=1; // 1 byte, all flags sets to 0
> > +                        *q++=0; // omit all fields...
> > +                    }
> >                  } else if (codec_id == AV_CODEC_ID_EAC3) {
> >                      *q++=0x7a; // EAC3 descriptor see A038 DVB SI
> >                      *q++=1; // 1 byte, all flags sets to 0
> > @@ -1843,6 +1865,63 @@ static int
> > mpegts_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
> >               * need to count the samples of that too! */
> >              av_log(s, AV_LOG_WARNING, "Got MPEG-TS formatted Opus data,
> > unhandled");
> >          }
> > +    } else if (st->codecpar->codec_id == AV_CODEC_ID_AC3 &&
> > !ts_st->dvb_ac3_desc) {
> > +         AC3HeaderInfo *hdr = NULL;
> > +
> > +        if (avpriv_ac3_parse_header(&hdr, pkt->data, pkt->size) >= 0) {
> > +            uint8_t number_of_channels_flag;
> > +            uint8_t service_type_flag;
> > +            uint8_t full_service_flag = 1;
> > +            DVBAC3Descriptor *dvb_ac3_desc;
> > +
> > +            dvb_ac3_desc = av_mallocz(sizeof(*dvb_ac3_desc));
> > +            if (!dvb_ac3_desc) {
> > +                av_free(hdr);
> > +                return AVERROR(ENOMEM);
> > +            }
> > +
> > +            service_type_flag = hdr->bitstream_mode;
> > +            switch (hdr->channel_mode) {
> > +                case AC3_CHMODE_DUALMONO:
> > +                    number_of_channels_flag = 1;
> > +                    break;
> > +                case AC3_CHMODE_MONO:
> > +                    number_of_channels_flag = 0;
> > +                    break;
> > +                case AC3_CHMODE_STEREO:
> > +                    if (hdr->dolby_surround_mode == AC3_DSURMOD_ON)
> > +                        number_of_channels_flag = 3;
> > +                    else
> > +                        number_of_channels_flag = 2;
> > +                    break;
> > +                case AC3_CHMODE_3F:
> > +                case AC3_CHMODE_2F1R:
> > +                case AC3_CHMODE_3F1R:
> > +                case AC3_CHMODE_2F2R:
> > +                case AC3_CHMODE_3F2R:
> > +                    number_of_channels_flag = 4;
> > +                    break;
> > +                default: /* reserved */
> > +                    number_of_channels_flag = 7;
> > +                    break;
> > +            }
> > +
> > +            if (service_type_flag  == 1 || service_type_flag == 4 ||
> > +                (service_type_flag == 7 && !number_of_channels_flag))
> > +                full_service_flag = 0;
> > +
> > +            dvb_ac3_desc->component_type_flag = 1;
> > +            dvb_ac3_desc->component_type = (full_service_flag << 6)
> >   |
> > +                                     ((service_type_flag      & 0x7) <<
> > 3) |
> > +                                     (number_of_channels_flag & 0x7);
> > +            dvb_ac3_desc->bsid_flag   = 1;
> > +            dvb_ac3_desc->bsid        = hdr->bitstream_id;
> > +            dvb_ac3_desc->mainid_flag = 0;
> > +            dvb_ac3_desc->asvc_flag   = 0;
> > +
> > +            ts_st->dvb_ac3_desc = dvb_ac3_desc;
> > +        }
> > +        av_free(hdr);
> >      }
> >
> >      if (ts_st->payload_size && (ts_st->payload_size + size >
> > ts->pes_payload_size ||
> > @@ -1934,6 +2013,7 @@ static void mpegts_deinit(AVFormatContext *s)
> >          AVStream *st = s->streams[i];
> >          MpegTSWriteStream *ts_st = st->priv_data;
> >          if (ts_st) {
> > +            av_freep(&ts_st->dvb_ac3_desc);
> >              av_freep(&ts_st->payload);
> >              if (ts_st->amux) {
> >                  avformat_free_context(ts_st->amux);
> > --
> > 1.8.3.1
> >
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel@ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
Limin Wang Aug. 22, 2020, 11:17 a.m. UTC | #3
On Sat, Aug 15, 2020 at 10:27:38PM +0800, lance.lmwang@gmail.com wrote:
> From: Limin Wang <lance.lmwang@gmail.com>
> 
> Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> ---
>  configure               |  2 +-
>  libavformat/mpegts.h    | 16 ++++++++++
>  libavformat/mpegtsenc.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++--
>  3 files changed, 99 insertions(+), 3 deletions(-)
> 
> diff --git a/configure b/configure
> index d4a1fea..a9d87b2 100755
> --- a/configure
> +++ b/configure
> @@ -3324,7 +3324,7 @@ mp3_demuxer_select="mpegaudio_parser"
>  mp3_muxer_select="mpegaudioheader"
>  mp4_muxer_select="mov_muxer"
>  mpegts_demuxer_select="iso_media"
> -mpegts_muxer_select="adts_muxer latm_muxer h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
> +mpegts_muxer_select="ac3_parser adts_muxer latm_muxer h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
>  mpegtsraw_demuxer_select="mpegts_demuxer"
>  mxf_muxer_select="golomb pcm_rechunk_bsf"
>  mxf_d10_muxer_select="mxf_muxer"
> diff --git a/libavformat/mpegts.h b/libavformat/mpegts.h
> index fe10b38..d70b25d 100644
> --- a/libavformat/mpegts.h
> +++ b/libavformat/mpegts.h
> @@ -175,6 +175,22 @@ typedef struct Mp4Descr {
>      SLConfigDescr sl;
>  } Mp4Descr;
>  
> +/*
> + * ETSI 300 468 descriptor 0x6A(AC-3)
> + * Refer to: ETSI EN 300 468 V1.11.1 (2010-04) (SI in DVB systems)
> + */
> +typedef struct DVBAC3Descriptor {
> +    uint8_t  component_type_flag;
> +    uint8_t  bsid_flag;
> +    uint8_t  mainid_flag;
> +    uint8_t  asvc_flag;
> +    uint8_t  reserved_flags;
> +    uint8_t  component_type;
> +    uint8_t  bsid;
> +    uint8_t  mainid;
> +    uint8_t  asvc;
> +} DVBAC3Descriptor;
> +
>  /**
>   * Parse an MPEG-2 descriptor
>   * @param[in] fc                    Format context (used for logging only)
> diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
> index 718ddab..876ba99 100644
> --- a/libavformat/mpegtsenc.c
> +++ b/libavformat/mpegtsenc.c
> @@ -27,6 +27,7 @@
>  #include "libavutil/mathematics.h"
>  #include "libavutil/opt.h"
>  
> +#include "libavcodec/ac3_parser_internal.h"
>  #include "libavcodec/internal.h"
>  
>  #include "avformat.h"
> @@ -244,6 +245,8 @@ typedef struct MpegTSWriteStream {
>      /* For Opus */
>      int opus_queued_samples;
>      int opus_pending_trim_start;
> +
> +    DVBAC3Descriptor *dvb_ac3_desc;
>  } MpegTSWriteStream;
>  
>  static void mpegts_write_pat(AVFormatContext *s)
> @@ -486,9 +489,28 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
>          case AVMEDIA_TYPE_AUDIO:
>              if (ts->flags & MPEGTS_FLAG_SYSTEM_B) {
>                  if (codec_id == AV_CODEC_ID_AC3) {
> +                    DVBAC3Descriptor *dvb_ac3_desc = ts_st->dvb_ac3_desc;
> +
>                      *q++=0x6a; // AC3 descriptor see A038 DVB SI
> -                    *q++=1; // 1 byte, all flags sets to 0
> -                    *q++=0; // omit all fields...
> +                    if (dvb_ac3_desc) {
> +                        int len = 1 +
> +                                  !!(dvb_ac3_desc->component_type_flag) +
> +                                  !!(dvb_ac3_desc->bsid_flag) +
> +                                  !!(dvb_ac3_desc->mainid_flag) +
> +                                  !!(dvb_ac3_desc->asvc_flag);
> +
> +                        *q++ = len;
> +                        *q++ = dvb_ac3_desc->component_type_flag << 7 | dvb_ac3_desc->bsid_flag << 6 |
> +                               dvb_ac3_desc->mainid_flag         << 5 | dvb_ac3_desc->asvc_flag << 4;
> +
> +                        if (dvb_ac3_desc->component_type_flag) *q++ = dvb_ac3_desc->component_type;
> +                        if (dvb_ac3_desc->bsid_flag)           *q++ = dvb_ac3_desc->bsid;
> +                        if (dvb_ac3_desc->mainid_flag)         *q++ = dvb_ac3_desc->mainid;
> +                        if (dvb_ac3_desc->asvc_flag)           *q++ = dvb_ac3_desc->asvc;
> +                    } else {
> +                        *q++=1; // 1 byte, all flags sets to 0
> +                        *q++=0; // omit all fields...
> +                    }
>                  } else if (codec_id == AV_CODEC_ID_EAC3) {
>                      *q++=0x7a; // EAC3 descriptor see A038 DVB SI
>                      *q++=1; // 1 byte, all flags sets to 0
> @@ -1843,6 +1865,63 @@ static int mpegts_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
>               * need to count the samples of that too! */
>              av_log(s, AV_LOG_WARNING, "Got MPEG-TS formatted Opus data, unhandled");
>          }
> +    } else if (st->codecpar->codec_id == AV_CODEC_ID_AC3 && !ts_st->dvb_ac3_desc) {
> +         AC3HeaderInfo *hdr = NULL;
> +
> +        if (avpriv_ac3_parse_header(&hdr, pkt->data, pkt->size) >= 0) {
> +            uint8_t number_of_channels_flag;
> +            uint8_t service_type_flag;
> +            uint8_t full_service_flag = 1;
> +            DVBAC3Descriptor *dvb_ac3_desc;
> +
> +            dvb_ac3_desc = av_mallocz(sizeof(*dvb_ac3_desc));
> +            if (!dvb_ac3_desc) {
> +                av_free(hdr);
> +                return AVERROR(ENOMEM);
> +            }
> +
> +            service_type_flag = hdr->bitstream_mode;
> +            switch (hdr->channel_mode) {
> +                case AC3_CHMODE_DUALMONO:
> +                    number_of_channels_flag = 1;
> +                    break;
> +                case AC3_CHMODE_MONO:
> +                    number_of_channels_flag = 0;
> +                    break;
> +                case AC3_CHMODE_STEREO:
> +                    if (hdr->dolby_surround_mode == AC3_DSURMOD_ON)
> +                        number_of_channels_flag = 3;
> +                    else
> +                        number_of_channels_flag = 2;
> +                    break;
> +                case AC3_CHMODE_3F:
> +                case AC3_CHMODE_2F1R:
> +                case AC3_CHMODE_3F1R:
> +                case AC3_CHMODE_2F2R:
> +                case AC3_CHMODE_3F2R:
> +                    number_of_channels_flag = 4;
> +                    break;
> +                default: /* reserved */
> +                    number_of_channels_flag = 7;
> +                    break;
> +            }
> +
> +            if (service_type_flag  == 1 || service_type_flag == 4 ||
> +                (service_type_flag == 7 && !number_of_channels_flag))
> +                full_service_flag = 0;
> +
> +            dvb_ac3_desc->component_type_flag = 1;
> +            dvb_ac3_desc->component_type = (full_service_flag << 6)        |
> +                                     ((service_type_flag      & 0x7) << 3) |
> +                                     (number_of_channels_flag & 0x7);
> +            dvb_ac3_desc->bsid_flag   = 1;
> +            dvb_ac3_desc->bsid        = hdr->bitstream_id;
> +            dvb_ac3_desc->mainid_flag = 0;
> +            dvb_ac3_desc->asvc_flag   = 0;
> +
> +            ts_st->dvb_ac3_desc = dvb_ac3_desc;
> +        }
> +        av_free(hdr);
>      }
>  
>      if (ts_st->payload_size && (ts_st->payload_size + size > ts->pes_payload_size ||
> @@ -1934,6 +2013,7 @@ static void mpegts_deinit(AVFormatContext *s)
>          AVStream *st = s->streams[i];
>          MpegTSWriteStream *ts_st = st->priv_data;
>          if (ts_st) {
> +            av_freep(&ts_st->dvb_ac3_desc);
>              av_freep(&ts_st->payload);
>              if (ts_st->amux) {
>                  avformat_free_context(ts_st->amux);
> -- 
> 1.8.3.1

ping, will apply it tomorrow if no objection.


>
Marton Balint Aug. 22, 2020, 5:36 p.m. UTC | #4
On Sat, 15 Aug 2020, lance.lmwang@gmail.com wrote:

> From: Limin Wang <lance.lmwang@gmail.com>
>
> Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> ---
> configure               |  2 +-
> libavformat/mpegts.h    | 16 ++++++++++
> libavformat/mpegtsenc.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++--
> 3 files changed, 99 insertions(+), 3 deletions(-)
>
> diff --git a/configure b/configure
> index d4a1fea..a9d87b2 100755
> --- a/configure
> +++ b/configure
> @@ -3324,7 +3324,7 @@ mp3_demuxer_select="mpegaudio_parser"
> mp3_muxer_select="mpegaudioheader"
> mp4_muxer_select="mov_muxer"
> mpegts_demuxer_select="iso_media"
> -mpegts_muxer_select="adts_muxer latm_muxer h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
> +mpegts_muxer_select="ac3_parser adts_muxer latm_muxer h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
> mpegtsraw_demuxer_select="mpegts_demuxer"
> mxf_muxer_select="golomb pcm_rechunk_bsf"
> mxf_d10_muxer_select="mxf_muxer"
> diff --git a/libavformat/mpegts.h b/libavformat/mpegts.h
> index fe10b38..d70b25d 100644
> --- a/libavformat/mpegts.h
> +++ b/libavformat/mpegts.h
> @@ -175,6 +175,22 @@ typedef struct Mp4Descr {
>     SLConfigDescr sl;
> } Mp4Descr;
> 
> +/*
> + * ETSI 300 468 descriptor 0x6A(AC-3)
> + * Refer to: ETSI EN 300 468 V1.11.1 (2010-04) (SI in DVB systems)
> + */
> +typedef struct DVBAC3Descriptor {
> +    uint8_t  component_type_flag;
> +    uint8_t  bsid_flag;
> +    uint8_t  mainid_flag;
> +    uint8_t  asvc_flag;
> +    uint8_t  reserved_flags;
> +    uint8_t  component_type;
> +    uint8_t  bsid;
> +    uint8_t  mainid;
> +    uint8_t  asvc;
> +} DVBAC3Descriptor;
> +
> /**
>  * Parse an MPEG-2 descriptor
>  * @param[in] fc                    Format context (used for logging only)
> diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
> index 718ddab..876ba99 100644
> --- a/libavformat/mpegtsenc.c
> +++ b/libavformat/mpegtsenc.c
> @@ -27,6 +27,7 @@
> #include "libavutil/mathematics.h"
> #include "libavutil/opt.h"
> 
> +#include "libavcodec/ac3_parser_internal.h"
> #include "libavcodec/internal.h"
> 
> #include "avformat.h"
> @@ -244,6 +245,8 @@ typedef struct MpegTSWriteStream {
>     /* For Opus */
>     int opus_queued_samples;
>     int opus_pending_trim_start;
> +
> +    DVBAC3Descriptor *dvb_ac3_desc;
> } MpegTSWriteStream;
> 
> static void mpegts_write_pat(AVFormatContext *s)
> @@ -486,9 +489,28 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
>         case AVMEDIA_TYPE_AUDIO:
>             if (ts->flags & MPEGTS_FLAG_SYSTEM_B) {
>                 if (codec_id == AV_CODEC_ID_AC3) {
> +                    DVBAC3Descriptor *dvb_ac3_desc = ts_st->dvb_ac3_desc;
> +
>                     *q++=0x6a; // AC3 descriptor see A038 DVB SI
> -                    *q++=1; // 1 byte, all flags sets to 0
> -                    *q++=0; // omit all fields...
> +                    if (dvb_ac3_desc) {
> +                        int len = 1 +
> +                                  !!(dvb_ac3_desc->component_type_flag) +
> +                                  !!(dvb_ac3_desc->bsid_flag) +
> +                                  !!(dvb_ac3_desc->mainid_flag) +
> +                                  !!(dvb_ac3_desc->asvc_flag);
> +
> +                        *q++ = len;
> +                        *q++ = dvb_ac3_desc->component_type_flag << 7 | dvb_ac3_desc->bsid_flag << 6 |
> +                               dvb_ac3_desc->mainid_flag         << 5 | dvb_ac3_desc->asvc_flag << 4;
> +
> +                        if (dvb_ac3_desc->component_type_flag) *q++ = dvb_ac3_desc->component_type;
> +                        if (dvb_ac3_desc->bsid_flag)           *q++ = dvb_ac3_desc->bsid;
> +                        if (dvb_ac3_desc->mainid_flag)         *q++ = dvb_ac3_desc->mainid;
> +                        if (dvb_ac3_desc->asvc_flag)           *q++ = dvb_ac3_desc->asvc;
> +                    } else {
> +                        *q++=1; // 1 byte, all flags sets to 0
> +                        *q++=0; // omit all fields...
> +                    }
>                 } else if (codec_id == AV_CODEC_ID_EAC3) {
>                     *q++=0x7a; // EAC3 descriptor see A038 DVB SI
>                     *q++=1; // 1 byte, all flags sets to 0
> @@ -1843,6 +1865,63 @@ static int mpegts_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
>              * need to count the samples of that too! */
>             av_log(s, AV_LOG_WARNING, "Got MPEG-TS formatted Opus data, unhandled");
>         }
> +    } else if (st->codecpar->codec_id == AV_CODEC_ID_AC3 && !ts_st->dvb_ac3_desc) {
> +         AC3HeaderInfo *hdr = NULL;

bad indentation

> +
> +        if (avpriv_ac3_parse_header(&hdr, pkt->data, pkt->size) >= 0) {
> +            uint8_t number_of_channels_flag;
> +            uint8_t service_type_flag;
> +            uint8_t full_service_flag = 1;
> +            DVBAC3Descriptor *dvb_ac3_desc;
> +
> +            dvb_ac3_desc = av_mallocz(sizeof(*dvb_ac3_desc));
> +            if (!dvb_ac3_desc) {
> +                av_free(hdr);
> +                return AVERROR(ENOMEM);
> +            }
> +
> +            service_type_flag = hdr->bitstream_mode;
> +            switch (hdr->channel_mode) {
> +                case AC3_CHMODE_DUALMONO:
> +                    number_of_channels_flag = 1;
> +                    break;
> +                case AC3_CHMODE_MONO:
> +                    number_of_channels_flag = 0;
> +                    break;
> +                case AC3_CHMODE_STEREO:
> +                    if (hdr->dolby_surround_mode == AC3_DSURMOD_ON)
> +                        number_of_channels_flag = 3;
> +                    else
> +                        number_of_channels_flag = 2;
> +                    break;
> +                case AC3_CHMODE_3F:
> +                case AC3_CHMODE_2F1R:
> +                case AC3_CHMODE_3F1R:
> +                case AC3_CHMODE_2F2R:
> +                case AC3_CHMODE_3F2R:
> +                    number_of_channels_flag = 4;
> +                    break;
> +                default: /* reserved */
> +                    number_of_channels_flag = 7;
> +                    break;
> +            }
> +
> +            if (service_type_flag  == 1 || service_type_flag == 4 ||
> +                (service_type_flag == 7 && !number_of_channels_flag))
> +                full_service_flag = 0;
> +
> +            dvb_ac3_desc->component_type_flag = 1;
> +            dvb_ac3_desc->component_type = (full_service_flag << 6)        |
> +                                     ((service_type_flag      & 0x7) << 3) |
> +                                     (number_of_channels_flag & 0x7);
> +            dvb_ac3_desc->bsid_flag   = 1;
> +            dvb_ac3_desc->bsid        = hdr->bitstream_id;
> +            dvb_ac3_desc->mainid_flag = 0;
> +            dvb_ac3_desc->asvc_flag   = 0;
> +
> +            ts_st->dvb_ac3_desc = dvb_ac3_desc;
> +        }
> +        av_free(hdr);
>     }
>
>     if (ts_st->payload_size && (ts_st->payload_size + size > ts->pes_payload_size ||
> @@ -1934,6 +2013,7 @@ static void mpegts_deinit(AVFormatContext *s)
>         AVStream *st = s->streams[i];
>         MpegTSWriteStream *ts_st = st->priv_data;
>         if (ts_st) {
> +            av_freep(&ts_st->dvb_ac3_desc);
>             av_freep(&ts_st->payload);
>             if (ts_st->amux) {
>                 avformat_free_context(ts_st->amux);

Looks good otherwise, thanks.

Marton
Limin Wang Aug. 22, 2020, 11:22 p.m. UTC | #5
On Sat, Aug 22, 2020 at 07:36:24PM +0200, Marton Balint wrote:
> 
> 
> On Sat, 15 Aug 2020, lance.lmwang@gmail.com wrote:
> 
> > From: Limin Wang <lance.lmwang@gmail.com>
> > 
> > Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> > ---
> > configure               |  2 +-
> > libavformat/mpegts.h    | 16 ++++++++++
> > libavformat/mpegtsenc.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++--
> > 3 files changed, 99 insertions(+), 3 deletions(-)
> > 
> > diff --git a/configure b/configure
> > index d4a1fea..a9d87b2 100755
> > --- a/configure
> > +++ b/configure
> > @@ -3324,7 +3324,7 @@ mp3_demuxer_select="mpegaudio_parser"
> > mp3_muxer_select="mpegaudioheader"
> > mp4_muxer_select="mov_muxer"
> > mpegts_demuxer_select="iso_media"
> > -mpegts_muxer_select="adts_muxer latm_muxer h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
> > +mpegts_muxer_select="ac3_parser adts_muxer latm_muxer h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
> > mpegtsraw_demuxer_select="mpegts_demuxer"
> > mxf_muxer_select="golomb pcm_rechunk_bsf"
> > mxf_d10_muxer_select="mxf_muxer"
> > diff --git a/libavformat/mpegts.h b/libavformat/mpegts.h
> > index fe10b38..d70b25d 100644
> > --- a/libavformat/mpegts.h
> > +++ b/libavformat/mpegts.h
> > @@ -175,6 +175,22 @@ typedef struct Mp4Descr {
> >     SLConfigDescr sl;
> > } Mp4Descr;
> > 
> > +/*
> > + * ETSI 300 468 descriptor 0x6A(AC-3)
> > + * Refer to: ETSI EN 300 468 V1.11.1 (2010-04) (SI in DVB systems)
> > + */
> > +typedef struct DVBAC3Descriptor {
> > +    uint8_t  component_type_flag;
> > +    uint8_t  bsid_flag;
> > +    uint8_t  mainid_flag;
> > +    uint8_t  asvc_flag;
> > +    uint8_t  reserved_flags;
> > +    uint8_t  component_type;
> > +    uint8_t  bsid;
> > +    uint8_t  mainid;
> > +    uint8_t  asvc;
> > +} DVBAC3Descriptor;
> > +
> > /**
> >  * Parse an MPEG-2 descriptor
> >  * @param[in] fc                    Format context (used for logging only)
> > diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
> > index 718ddab..876ba99 100644
> > --- a/libavformat/mpegtsenc.c
> > +++ b/libavformat/mpegtsenc.c
> > @@ -27,6 +27,7 @@
> > #include "libavutil/mathematics.h"
> > #include "libavutil/opt.h"
> > 
> > +#include "libavcodec/ac3_parser_internal.h"
> > #include "libavcodec/internal.h"
> > 
> > #include "avformat.h"
> > @@ -244,6 +245,8 @@ typedef struct MpegTSWriteStream {
> >     /* For Opus */
> >     int opus_queued_samples;
> >     int opus_pending_trim_start;
> > +
> > +    DVBAC3Descriptor *dvb_ac3_desc;
> > } MpegTSWriteStream;
> > 
> > static void mpegts_write_pat(AVFormatContext *s)
> > @@ -486,9 +489,28 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
> >         case AVMEDIA_TYPE_AUDIO:
> >             if (ts->flags & MPEGTS_FLAG_SYSTEM_B) {
> >                 if (codec_id == AV_CODEC_ID_AC3) {
> > +                    DVBAC3Descriptor *dvb_ac3_desc = ts_st->dvb_ac3_desc;
> > +
> >                     *q++=0x6a; // AC3 descriptor see A038 DVB SI
> > -                    *q++=1; // 1 byte, all flags sets to 0
> > -                    *q++=0; // omit all fields...
> > +                    if (dvb_ac3_desc) {
> > +                        int len = 1 +
> > +                                  !!(dvb_ac3_desc->component_type_flag) +
> > +                                  !!(dvb_ac3_desc->bsid_flag) +
> > +                                  !!(dvb_ac3_desc->mainid_flag) +
> > +                                  !!(dvb_ac3_desc->asvc_flag);
> > +
> > +                        *q++ = len;
> > +                        *q++ = dvb_ac3_desc->component_type_flag << 7 | dvb_ac3_desc->bsid_flag << 6 |
> > +                               dvb_ac3_desc->mainid_flag         << 5 | dvb_ac3_desc->asvc_flag << 4;
> > +
> > +                        if (dvb_ac3_desc->component_type_flag) *q++ = dvb_ac3_desc->component_type;
> > +                        if (dvb_ac3_desc->bsid_flag)           *q++ = dvb_ac3_desc->bsid;
> > +                        if (dvb_ac3_desc->mainid_flag)         *q++ = dvb_ac3_desc->mainid;
> > +                        if (dvb_ac3_desc->asvc_flag)           *q++ = dvb_ac3_desc->asvc;
> > +                    } else {
> > +                        *q++=1; // 1 byte, all flags sets to 0
> > +                        *q++=0; // omit all fields...
> > +                    }
> >                 } else if (codec_id == AV_CODEC_ID_EAC3) {
> >                     *q++=0x7a; // EAC3 descriptor see A038 DVB SI
> >                     *q++=1; // 1 byte, all flags sets to 0
> > @@ -1843,6 +1865,63 @@ static int mpegts_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
> >              * need to count the samples of that too! */
> >             av_log(s, AV_LOG_WARNING, "Got MPEG-TS formatted Opus data, unhandled");
> >         }
> > +    } else if (st->codecpar->codec_id == AV_CODEC_ID_AC3 && !ts_st->dvb_ac3_desc) {
> > +         AC3HeaderInfo *hdr = NULL;
> 
> bad indentation
> 
> > +
> > +        if (avpriv_ac3_parse_header(&hdr, pkt->data, pkt->size) >= 0) {
> > +            uint8_t number_of_channels_flag;
> > +            uint8_t service_type_flag;
> > +            uint8_t full_service_flag = 1;
> > +            DVBAC3Descriptor *dvb_ac3_desc;
> > +
> > +            dvb_ac3_desc = av_mallocz(sizeof(*dvb_ac3_desc));
> > +            if (!dvb_ac3_desc) {
> > +                av_free(hdr);
> > +                return AVERROR(ENOMEM);
> > +            }
> > +
> > +            service_type_flag = hdr->bitstream_mode;
> > +            switch (hdr->channel_mode) {
> > +                case AC3_CHMODE_DUALMONO:
> > +                    number_of_channels_flag = 1;
> > +                    break;
> > +                case AC3_CHMODE_MONO:
> > +                    number_of_channels_flag = 0;
> > +                    break;
> > +                case AC3_CHMODE_STEREO:
> > +                    if (hdr->dolby_surround_mode == AC3_DSURMOD_ON)
> > +                        number_of_channels_flag = 3;
> > +                    else
> > +                        number_of_channels_flag = 2;
> > +                    break;
> > +                case AC3_CHMODE_3F:
> > +                case AC3_CHMODE_2F1R:
> > +                case AC3_CHMODE_3F1R:
> > +                case AC3_CHMODE_2F2R:
> > +                case AC3_CHMODE_3F2R:
> > +                    number_of_channels_flag = 4;
> > +                    break;
> > +                default: /* reserved */
> > +                    number_of_channels_flag = 7;
> > +                    break;
> > +            }
> > +
> > +            if (service_type_flag  == 1 || service_type_flag == 4 ||
> > +                (service_type_flag == 7 && !number_of_channels_flag))
> > +                full_service_flag = 0;
> > +
> > +            dvb_ac3_desc->component_type_flag = 1;
> > +            dvb_ac3_desc->component_type = (full_service_flag << 6)        |
> > +                                     ((service_type_flag      & 0x7) << 3) |
> > +                                     (number_of_channels_flag & 0x7);
> > +            dvb_ac3_desc->bsid_flag   = 1;
> > +            dvb_ac3_desc->bsid        = hdr->bitstream_id;
> > +            dvb_ac3_desc->mainid_flag = 0;
> > +            dvb_ac3_desc->asvc_flag   = 0;
> > +
> > +            ts_st->dvb_ac3_desc = dvb_ac3_desc;
> > +        }
> > +        av_free(hdr);
> >     }
> > 
> >     if (ts_st->payload_size && (ts_st->payload_size + size > ts->pes_payload_size ||
> > @@ -1934,6 +2013,7 @@ static void mpegts_deinit(AVFormatContext *s)
> >         AVStream *st = s->streams[i];
> >         MpegTSWriteStream *ts_st = st->priv_data;
> >         if (ts_st) {
> > +            av_freep(&ts_st->dvb_ac3_desc);
> >             av_freep(&ts_st->payload);
> >             if (ts_st->amux) {
> >                 avformat_free_context(ts_st->amux);
> 
> Looks good otherwise, thanks.

thanks, fix the indention and pushed.

> 
> Marton
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
diff mbox series

Patch

diff --git a/configure b/configure
index d4a1fea..a9d87b2 100755
--- a/configure
+++ b/configure
@@ -3324,7 +3324,7 @@  mp3_demuxer_select="mpegaudio_parser"
 mp3_muxer_select="mpegaudioheader"
 mp4_muxer_select="mov_muxer"
 mpegts_demuxer_select="iso_media"
-mpegts_muxer_select="adts_muxer latm_muxer h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
+mpegts_muxer_select="ac3_parser adts_muxer latm_muxer h264_mp4toannexb_bsf hevc_mp4toannexb_bsf"
 mpegtsraw_demuxer_select="mpegts_demuxer"
 mxf_muxer_select="golomb pcm_rechunk_bsf"
 mxf_d10_muxer_select="mxf_muxer"
diff --git a/libavformat/mpegts.h b/libavformat/mpegts.h
index fe10b38..d70b25d 100644
--- a/libavformat/mpegts.h
+++ b/libavformat/mpegts.h
@@ -175,6 +175,22 @@  typedef struct Mp4Descr {
     SLConfigDescr sl;
 } Mp4Descr;
 
+/*
+ * ETSI 300 468 descriptor 0x6A(AC-3)
+ * Refer to: ETSI EN 300 468 V1.11.1 (2010-04) (SI in DVB systems)
+ */
+typedef struct DVBAC3Descriptor {
+    uint8_t  component_type_flag;
+    uint8_t  bsid_flag;
+    uint8_t  mainid_flag;
+    uint8_t  asvc_flag;
+    uint8_t  reserved_flags;
+    uint8_t  component_type;
+    uint8_t  bsid;
+    uint8_t  mainid;
+    uint8_t  asvc;
+} DVBAC3Descriptor;
+
 /**
  * Parse an MPEG-2 descriptor
  * @param[in] fc                    Format context (used for logging only)
diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
index 718ddab..876ba99 100644
--- a/libavformat/mpegtsenc.c
+++ b/libavformat/mpegtsenc.c
@@ -27,6 +27,7 @@ 
 #include "libavutil/mathematics.h"
 #include "libavutil/opt.h"
 
+#include "libavcodec/ac3_parser_internal.h"
 #include "libavcodec/internal.h"
 
 #include "avformat.h"
@@ -244,6 +245,8 @@  typedef struct MpegTSWriteStream {
     /* For Opus */
     int opus_queued_samples;
     int opus_pending_trim_start;
+
+    DVBAC3Descriptor *dvb_ac3_desc;
 } MpegTSWriteStream;
 
 static void mpegts_write_pat(AVFormatContext *s)
@@ -486,9 +489,28 @@  static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
         case AVMEDIA_TYPE_AUDIO:
             if (ts->flags & MPEGTS_FLAG_SYSTEM_B) {
                 if (codec_id == AV_CODEC_ID_AC3) {
+                    DVBAC3Descriptor *dvb_ac3_desc = ts_st->dvb_ac3_desc;
+
                     *q++=0x6a; // AC3 descriptor see A038 DVB SI
-                    *q++=1; // 1 byte, all flags sets to 0
-                    *q++=0; // omit all fields...
+                    if (dvb_ac3_desc) {
+                        int len = 1 +
+                                  !!(dvb_ac3_desc->component_type_flag) +
+                                  !!(dvb_ac3_desc->bsid_flag) +
+                                  !!(dvb_ac3_desc->mainid_flag) +
+                                  !!(dvb_ac3_desc->asvc_flag);
+
+                        *q++ = len;
+                        *q++ = dvb_ac3_desc->component_type_flag << 7 | dvb_ac3_desc->bsid_flag << 6 |
+                               dvb_ac3_desc->mainid_flag         << 5 | dvb_ac3_desc->asvc_flag << 4;
+
+                        if (dvb_ac3_desc->component_type_flag) *q++ = dvb_ac3_desc->component_type;
+                        if (dvb_ac3_desc->bsid_flag)           *q++ = dvb_ac3_desc->bsid;
+                        if (dvb_ac3_desc->mainid_flag)         *q++ = dvb_ac3_desc->mainid;
+                        if (dvb_ac3_desc->asvc_flag)           *q++ = dvb_ac3_desc->asvc;
+                    } else {
+                        *q++=1; // 1 byte, all flags sets to 0
+                        *q++=0; // omit all fields...
+                    }
                 } else if (codec_id == AV_CODEC_ID_EAC3) {
                     *q++=0x7a; // EAC3 descriptor see A038 DVB SI
                     *q++=1; // 1 byte, all flags sets to 0
@@ -1843,6 +1865,63 @@  static int mpegts_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
              * need to count the samples of that too! */
             av_log(s, AV_LOG_WARNING, "Got MPEG-TS formatted Opus data, unhandled");
         }
+    } else if (st->codecpar->codec_id == AV_CODEC_ID_AC3 && !ts_st->dvb_ac3_desc) {
+         AC3HeaderInfo *hdr = NULL;
+
+        if (avpriv_ac3_parse_header(&hdr, pkt->data, pkt->size) >= 0) {
+            uint8_t number_of_channels_flag;
+            uint8_t service_type_flag;
+            uint8_t full_service_flag = 1;
+            DVBAC3Descriptor *dvb_ac3_desc;
+
+            dvb_ac3_desc = av_mallocz(sizeof(*dvb_ac3_desc));
+            if (!dvb_ac3_desc) {
+                av_free(hdr);
+                return AVERROR(ENOMEM);
+            }
+
+            service_type_flag = hdr->bitstream_mode;
+            switch (hdr->channel_mode) {
+                case AC3_CHMODE_DUALMONO:
+                    number_of_channels_flag = 1;
+                    break;
+                case AC3_CHMODE_MONO:
+                    number_of_channels_flag = 0;
+                    break;
+                case AC3_CHMODE_STEREO:
+                    if (hdr->dolby_surround_mode == AC3_DSURMOD_ON)
+                        number_of_channels_flag = 3;
+                    else
+                        number_of_channels_flag = 2;
+                    break;
+                case AC3_CHMODE_3F:
+                case AC3_CHMODE_2F1R:
+                case AC3_CHMODE_3F1R:
+                case AC3_CHMODE_2F2R:
+                case AC3_CHMODE_3F2R:
+                    number_of_channels_flag = 4;
+                    break;
+                default: /* reserved */
+                    number_of_channels_flag = 7;
+                    break;
+            }
+
+            if (service_type_flag  == 1 || service_type_flag == 4 ||
+                (service_type_flag == 7 && !number_of_channels_flag))
+                full_service_flag = 0;
+
+            dvb_ac3_desc->component_type_flag = 1;
+            dvb_ac3_desc->component_type = (full_service_flag << 6)        |
+                                     ((service_type_flag      & 0x7) << 3) |
+                                     (number_of_channels_flag & 0x7);
+            dvb_ac3_desc->bsid_flag   = 1;
+            dvb_ac3_desc->bsid        = hdr->bitstream_id;
+            dvb_ac3_desc->mainid_flag = 0;
+            dvb_ac3_desc->asvc_flag   = 0;
+
+            ts_st->dvb_ac3_desc = dvb_ac3_desc;
+        }
+        av_free(hdr);
     }
 
     if (ts_st->payload_size && (ts_st->payload_size + size > ts->pes_payload_size ||
@@ -1934,6 +2013,7 @@  static void mpegts_deinit(AVFormatContext *s)
         AVStream *st = s->streams[i];
         MpegTSWriteStream *ts_st = st->priv_data;
         if (ts_st) {
+            av_freep(&ts_st->dvb_ac3_desc);
             av_freep(&ts_st->payload);
             if (ts_st->amux) {
                 avformat_free_context(ts_st->amux);