[FFmpeg-devel] libavformat/mpegtsenc: fix incorrect PCR with multiple programs [v4]
Andriy Gelman
andriy.gelman at gmail.com
Thu Aug 1 01:23:23 EEST 2019
Andreas,
On Mon, 29. Jul 11:11, Andreas Håkon wrote:
> Hi,
>
> An updated version that fixes all previous bugs:
> https://patchwork.ffmpeg.org/patch/14109/
> https://patchwork.ffmpeg.org/patch/14099/
> https://patchwork.ffmpeg.org/patch/14036/
>
> It passes the tests pointed by Michael Niedermayer (Sample_cut.ts) and
> Andriy Gelman (day_flight.mpg).
>
> I hope this time the patch will be accepted.
> Regards.
> A.H.
>
> ---
> From 8381febd0e881cfcd53583b0ccdd7eb2c580e422 Mon Sep 17 00:00:00 2001
> From: Andreas Hakon <andreas.hakon at protonmail.com>
> Date: Mon, 29 Jul 2019 12:02:06 +0100
> Subject: [PATCH] libavformat/mpegtsenc: fix incorrect PCR with multiple
> programs [v4]
>
> The MPEG-TS muxer has a serious bug related to the use of multiple programs:
> in that case, the PCR pid selection is incomplete for all services except one.
> This patch solves this problem and select correct streams for each program.
> Furthermore, it passes all the checks and doesn't generate any regression.
> Also fully compatible with shared pids over services.
>
> You can check it with this example command:
>
> $ ./ffmpeg -loglevel verbose -y -f data -i /dev/zero \
> -filter_complex "nullsrc=s=60x60,split=2[v0][v1],anullsrc[a]" \
> -map [v0] -c:v:0 rawvideo \
> -map [v1] -c:v:1 rawvideo \
> -map [a] -c:a:0 pcm_s8 \
> -program st=0,2 -program st=1,2 -program st=2 -program st=0 -f mpegts out.ts
>
> And you will see something like:
>
> [mpegts @ 0x55f8452797c0] service 1 using PCR in pid=256
> [mpegts @ 0x55f8452797c0] service 2 using PCR in pid=257
> [mpegts @ 0x55f8452797c0] service 3 using PCR in pid=258
> [mpegts @ 0x55f8452797c0] service 4 using PCR in pid=256
>
>
> Signed-off-by: Andreas Hakon <andreas.hakon at protonmail.com>
> ---
> libavformat/mpegtsenc.c | 167 +++++++++++++++++++++++++++++------------------
> 1 file changed, 105 insertions(+), 62 deletions(-)
>
> diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
> index fc0ea22..6a0dd55 100644
> --- a/libavformat/mpegtsenc.c
> +++ b/libavformat/mpegtsenc.c
> @@ -60,6 +60,7 @@ typedef struct MpegTSService {
> int pcr_packet_count;
> int pcr_packet_period;
> AVProgram *program;
> + AVStream *pcr_st;
> } MpegTSService;
>
> // service_type values as defined in ETSI 300 468
> @@ -774,7 +775,7 @@ static int mpegts_init(AVFormatContext *s)
> MpegTSWrite *ts = s->priv_data;
> MpegTSWriteStream *ts_st;
> MpegTSService *service;
> - AVStream *st, *pcr_st = NULL;
> + AVStream *st;
> AVDictionaryEntry *title, *provider;
> int i, j;
> const char *service_name;
> @@ -831,6 +832,11 @@ static int mpegts_init(AVFormatContext *s)
> }
> }
>
> + for (i = 0; i < ts->nb_services; i++) {
> + service = ts->services[i];
> + service->pcr_st = NULL;
> + }
> +
If you are going to add pcr_st to MpegTSService then it would make sense to move the
initialization to mpegts_add_service function.
> ts->pat.pid = PAT_PID;
> /* Initialize at 15 so that it wraps and is equal to 0 for the
> * first packet we write. */
> @@ -872,17 +878,6 @@ static int mpegts_init(AVFormatContext *s)
> goto fail;
> }
>
> - program = av_find_program_from_stream(s, NULL, i);
> - if (program) {
> - for (j = 0; j < ts->nb_services; j++) {
> - if (ts->services[j]->program == program) {
> - service = ts->services[j];
> - break;
> - }
> - }
> - }
> -
> - ts_st->service = service;
> /* MPEG pid values < 16 are reserved. Applications which set st->id in
> * this range are assigned a calculated pid. */
> if (st->id < 16) {
> @@ -895,11 +890,6 @@ static int mpegts_init(AVFormatContext *s)
> ret = AVERROR(EINVAL);
> goto fail;
> }
> - if (ts_st->pid == service->pmt.pid) {
> - av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", ts_st->pid);
> - ret = AVERROR(EINVAL);
> - goto fail;
> - }
> for (j = 0; j < i; j++) {
> if (pids[j] == ts_st->pid) {
> av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", ts_st->pid);
> @@ -913,12 +903,7 @@ static int mpegts_init(AVFormatContext *s)
> ts_st->first_pts_check = 1;
> ts_st->cc = 15;
> ts_st->discontinuity = ts->flags & MPEGTS_FLAG_DISCONT;
> - /* update PCR pid by using the first video stream */
> - if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
> - service->pcr_pid == 0x1fff) {
> - service->pcr_pid = ts_st->pid;
> - pcr_st = st;
> - }
> +
> if (st->codecpar->codec_id == AV_CODEC_ID_AAC &&
> st->codecpar->extradata_size > 0) {
> AVStream *ast;
> @@ -949,50 +934,109 @@ static int mpegts_init(AVFormatContext *s)
> if (st->codecpar->codec_id == AV_CODEC_ID_OPUS) {
> ts_st->opus_pending_trim_start = st->codecpar->initial_padding * 48000 / st->codecpar->sample_rate;
> }
> +
> + /* program service checks */
> + program = av_find_program_from_stream(s, NULL, i);
> + do {
> + for (j = 0; j < ts->nb_services; j++) {
> + if (program) {
> + /* search for the services corresponding to this program */
> + if (ts->services[j]->program == program)
> + service = ts->services[j];
> + else
> + continue;
> + }
> +
> + ts_st->service = service;
> +
> + /* check for PMT pid conflicts */
> + if (ts_st->pid == service->pmt.pid) {
> + av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", ts_st->pid);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> +
> + /* update PCR pid by using the first video stream */
> + if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
> + service->pcr_pid == 0x1fff) {
> + service->pcr_pid = ts_st->pid;
> + service->pcr_st = st;
> + }
> +
> + /* store this stream as a candidate PCR if the service doesn't have any */
> + if (service->pcr_pid == 0x1fff &&
> + !service->pcr_st) {
> + service->pcr_st = st;
> + }
> +
> + /* exit when just one single service */
> + if (!program)
> + break;
> + }
> + program = program ? av_find_program_from_stream(s, program, i) : NULL;
> + } while (program);
This may be easier to digest if you separate the cases when
s->nb_programs == 0 and s->nb_programs > 0. Maybe something like this could
work:
/*update service when no programs defined. use default service */
if (s->nb_programs == 0) {
ret = update_service_and_set_pcr(s, st, service);
if (ret < 0)
goto fail:
}
/*find program for i-th stream */
program = av_find_program_from_stream(s, NULL, i);
while (s->nb_programs > 0 && program) {
/*find the service that this program belongs to */
for (j = 0; j < ts->nb_services; j++) {
if (ts->services[j]->program == program) {
service = ts->services[j];
break;
}
}
ret = update_service_and_set_pcr(s, st, service);
if (ret < 0)
goto fail:
/*find next program that this stream belongs to */
program = av_find_program_from_stream(s, program, i);
}
/*we need to define the function update_service_and_set_pcr */
static int update_service_and_set_pcr(AVFormatContext *s, AVStream *st, MpegTSService *service)
{
MpegTSWriteStream *ts_st = st->priv_data;
ts_st->service = service;
/* check for PMT pid conflicts */
if (ts_st->pid == service->pmt.pid) {
av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", ts_st->pid);
return AVERROR(EINVAL);
}
/* update PCR pid by using the first video stream */
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
service->pcr_pid == 0x1fff) {
service->pcr_pid = ts_st->pid;
service->pcr_st = st;
}
/* store this stream as a candidate PCR if the service doesn't have any */
if (service->pcr_pid == 0x1fff)
service->pcr_st = st;
return 0;
}
> }
>
> av_freep(&pids);
>
> - /* if no video stream, use the first stream as PCR */
> - if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {
> - pcr_st = s->streams[0];
> - ts_st = pcr_st->priv_data;
> - service->pcr_pid = ts_st->pid;
> - } else
> - ts_st = pcr_st->priv_data;
> -
> - if (ts->mux_rate > 1) {
> - service->pcr_packet_period = (int64_t)ts->mux_rate * ts->pcr_period /
> - (TS_PACKET_SIZE * 8 * 1000);
> - ts->sdt_packet_period = (int64_t)ts->mux_rate * SDT_RETRANS_TIME /
> - (TS_PACKET_SIZE * 8 * 1000);
> - ts->pat_packet_period = (int64_t)ts->mux_rate * PAT_RETRANS_TIME /
> - (TS_PACKET_SIZE * 8 * 1000);
> -
> - if (ts->copyts < 1)
> - ts->first_pcr = av_rescale(s->max_delay, PCR_TIME_BASE, AV_TIME_BASE);
> - } else {
> - /* Arbitrary values, PAT/PMT will also be written on video key frames */
> - ts->sdt_packet_period = 200;
> - ts->pat_packet_period = 40;
> - if (pcr_st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
> - int frame_size = av_get_audio_frame_duration2(pcr_st->codecpar, 0);
> - if (!frame_size) {
> - av_log(s, AV_LOG_WARNING, "frame size not set\n");
> - service->pcr_packet_period =
> - pcr_st->codecpar->sample_rate / (10 * 512);
> + for (i = 0; i < ts->nb_services; i++) {
> + service = ts->services[i];
> +
> + if (!service->pcr_st) {
> + av_log(s, AV_LOG_ERROR, "no PCR selected for the service %i\n", service->sid);
> + ret = AVERROR(EINVAL);
> + goto fail_at_end;
fail_at_end is not deallocating any memory.
Just return AVERROR(EINVAL) instead of goto would be fine.
> + }
> + /* get the PCR stream (real or candidate) */
> + ts_st = service->pcr_st->priv_data;
> +
> + /* if no video stream then use the pid of the candidate PCR */
> + if (service->pcr_pid == 0x1fff)
> + service->pcr_pid = ts_st->pid;
> +
> + if (ts->mux_rate > 1) {
> + service->pcr_packet_period = (int64_t)ts->mux_rate * ts->pcr_period /
> + (TS_PACKET_SIZE * 8 * 1000);
> + ts->sdt_packet_period = (int64_t)ts->mux_rate * SDT_RETRANS_TIME /
> + (TS_PACKET_SIZE * 8 * 1000);
> + ts->pat_packet_period = (int64_t)ts->mux_rate * PAT_RETRANS_TIME /
> + (TS_PACKET_SIZE * 8 * 1000);
> + if (ts->copyts < 1)
> + ts->first_pcr = av_rescale(s->max_delay, PCR_TIME_BASE, AV_TIME_BASE);
> + } else {
> + /* Arbitrary values, PAT/PMT will also be written on video key frames */
> + ts->sdt_packet_period = 200;
> + ts->pat_packet_period = 40;
> + if (service->pcr_st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
> + int frame_size = av_get_audio_frame_duration2(service->pcr_st->codecpar, 0);
> + if (!frame_size) {
> + av_log(s, AV_LOG_WARNING, "frame size not set\n");
> + service->pcr_packet_period =
> + service->pcr_st->codecpar->sample_rate / (10 * 512);
> + } else {
> + service->pcr_packet_period =
> + service->pcr_st->codecpar->sample_rate / (10 * frame_size);
> + }
> } else {
> + // max delta PCR 0.1s
> + // TODO: should be avg_frame_rate
> service->pcr_packet_period =
> - pcr_st->codecpar->sample_rate / (10 * frame_size);
> + ts_st->user_tb.den / (10 * ts_st->user_tb.num);
> }
> - } else {
> - // max delta PCR 0.1s
> - // TODO: should be avg_frame_rate
> - service->pcr_packet_period =
> - ts_st->user_tb.den / (10 * ts_st->user_tb.num);
> + if (!service->pcr_packet_period)
> + service->pcr_packet_period = 1;
> }
> - if (!service->pcr_packet_period)
> - service->pcr_packet_period = 1;
> +
> + // output a PCR as soon as possible
> + service->pcr_packet_count = service->pcr_packet_period;
> +
> + av_log(s, AV_LOG_VERBOSE, "service %i using PCR in pid=%i\n", service->sid, service->pcr_pid);
> + }
> +
> + if (!ts_st->service) {
> + av_log(s, AV_LOG_ERROR, "empty services!\n");
> + ret = AVERROR(EINVAL);
> + goto fail_at_end;
> }
This is outside the stream loop, so why the random check?
>
> ts->last_pat_ts = AV_NOPTS_VALUE;
> @@ -1005,8 +1049,6 @@ static int mpegts_init(AVFormatContext *s)
> ts->sdt_packet_period = INT_MAX;
> }
>
> - // output a PCR as soon as possible
> - service->pcr_packet_count = service->pcr_packet_period;
> ts->pat_packet_count = ts->pat_packet_period - 1;
> ts->sdt_packet_count = ts->sdt_packet_period - 1;
>
> @@ -1016,7 +1058,7 @@ static int mpegts_init(AVFormatContext *s)
> av_log(s, AV_LOG_VERBOSE, "muxrate %d, ", ts->mux_rate);
> av_log(s, AV_LOG_VERBOSE,
> "pcr every %d pkts, sdt every %d, pat/pmt every %d pkts\n",
> - service->pcr_packet_period,
> + ts_st->service->pcr_packet_period,
> ts->sdt_packet_period, ts->pat_packet_period);
>
> if (ts->m2ts_mode == -1) {
> @@ -1031,6 +1073,7 @@ static int mpegts_init(AVFormatContext *s)
>
> fail:
> av_freep(&pids);
> +fail_at_end:
> return ret;
I don't think you need this goto option.
> }
>
> --
> 1.7.10.4
>
Andriy
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