[FFmpeg-devel] [PATCH 1/2] avformat/mpegtsenc: support DVB 6A descriptor for AC-3
lance.lmwang at gmail.com
lance.lmwang at gmail.com
Sat Aug 15 16:01:07 EEST 2020
On Fri, Aug 14, 2020 at 10:29:45PM +0200, Marton Balint wrote:
>
>
> On Fri, 14 Aug 2020, lance.lmwang at gmail.com wrote:
>
> > From: Limin Wang <lance.lmwang at gmail.com>
> >
> > Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> > ---
> > Sorry, fix for the patch order for fate test
> >
> > libavformat/mpegts.h | 16 +++++++++++
> > libavformat/mpegtsenc.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++
>
> I think the ac3_parser dependency of the mpegts muxer should be added to
> configure.
sure, will add the dependency to configure
>
> > 2 files changed, 92 insertions(+)
> >
> > diff --git a/libavformat/mpegts.h b/libavformat/mpegts.h
> > index fe10b38..951aa61 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 AVDVBAC3Descriptor {
> > + 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;
> > +} AVDVBAC3Descriptor;
>
> As others suggested, remove AV prefix.
OK
>
> > +
> > /**
> > * 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..e9ac08d 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;
> > +
> > + AVDVBAC3Descriptor *desc6a;
>
> Sorry, can you name the variable dvb_ac3_desc or something? This 6a still
> does not speak for itself...
sure, will fix it.
>
> > } 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) {
> > + AVDVBAC3Descriptor *desc6a = ts_st->desc6a;
> > +
> > *q++=0x6a; // AC3 descriptor see A038 DVB SI
> > + if (desc6a) {
> > + int len = 1 +
> > + !!(desc6a->component_type_flag) +
> > + !!(desc6a->bsid_flag) +
> > + !!(desc6a->mainid_flag) +
> > + !!(desc6a->asvc_flag);
> > +
> > + *q++ = len;
> > + *q++ = desc6a->component_type_flag << 7 | desc6a->bsid_flag << 6 |
> > + desc6a->mainid_flag << 5 | desc6a->asvc_flag << 4;
> > +
> > + if (desc6a->component_type_flag) *q++ = desc6a->component_type;
> > + if (desc6a->bsid_flag) *q++ = desc6a->bsid;
> > + if (desc6a->mainid_flag) *q++ = desc6a->mainid;
> > + if (desc6a->asvc_flag) *q++ = desc6a->asvc;
> > + } else {
> > *q++=1; // 1 byte, all flags sets to 0
> > *q++=0; // omit all fields...
>
> I think these two lines are small enough to reindent in the same patch.
OK, will fix it
>
> > + }
> > } 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 +1865,59 @@ 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->desc6a) {
> > + uint8_t number_of_channels_flag;
> > + uint8_t service_type_flag;
> > + uint8_t full_service_flag = 1;
> > + AC3HeaderInfo *hdr = NULL;
> > + AVDVBAC3Descriptor *desc6a;
>
> push most of these initializers one level down
OK
>
> > +
> > + if (avpriv_ac3_parse_header(&hdr, pkt->data, pkt->size) >= 0) {
>
> Aren't you leaking hdr in the return path and at the end of this block?
Haven't notice the hdr will allocate memory, will fix it.
>
> > + desc6a = av_mallocz(sizeof(*desc6a));
> > + if (!desc6a)
> > + 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;
> > +
> > + desc6a->component_type_flag = 1;
> > + desc6a->component_type = (full_service_flag << 6) |
> > + ((service_type_flag & 0x7) << 3) |
> > + (number_of_channels_flag & 0x7);
> > + desc6a->bsid_flag = 1;
> > + desc6a->bsid = hdr->bitstream_id;
> > + desc6a->mainid_flag = 0;
> > + desc6a->asvc_flag = 0;
> > +
> > + ts_st->desc6a = desc6a;
> > + }
> > }
> >
> > if (ts_st->payload_size && (ts_st->payload_size + size > ts->pes_payload_size ||
> > @@ -1934,6 +2009,7 @@ static void mpegts_deinit(AVFormatContext *s)
> > AVStream *st = s->streams[i];
> > MpegTSWriteStream *ts_st = st->priv_data;
> > if (ts_st) {
> > + av_freep(&ts_st->desc6a);
> > av_freep(&ts_st->payload);
> > if (ts_st->amux) {
> > avformat_free_context(ts_st->amux);
> > --
>
> Regards,
> Marton
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--
Thanks,
Limin Wang
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