> On Oct 27, 2016, at 02:07, Steven Liu <lingjiujia...@gmail.com> wrote: > > 2016-10-27 15:01 GMT+08:00 Steven Liu <lingjiujia...@gmail.com > <mailto:lingjiujia...@gmail.com>>: > >> >> >> 2016-10-27 14:52 GMT+08:00 Rodger Combs <rodger.co...@gmail.com>: >> >>> >>>> On Oct 27, 2016, at 01:41, Steven Liu <lingjiujia...@gmail.com> wrote: >>>> >>>> 2016-10-27 14:16 GMT+08:00 Rodger Combs <rodger.co...@gmail.com>: >>>> >>>>> --- >>>>> libavformat/segment.c | 40 +++++++++++++++++++++++++++++++++++++++- >>>>> 1 file changed, 39 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/libavformat/segment.c b/libavformat/segment.c >>>>> index 868f0a8..9b3dc17 100644 >>>>> --- a/libavformat/segment.c >>>>> +++ b/libavformat/segment.c >>>>> @@ -798,9 +798,26 @@ static int seg_write_header(AVFormatContext *s) >>>>> { >>>>> SegmentContext *seg = s->priv_data; >>>>> AVFormatContext *oc = seg->avf; >>>>> - int ret; >>>>> + int ret, i; >>>>> >>>>> if (!seg->header_written) { >>>>> + for (i = 0; i < s->nb_streams; i++) { >>>>> + AVStream *st = oc->streams[i]; >>>>> + AVCodecParameters *ipar, *opar; >>>>> + >>>>> + ipar = s->streams[i]->codecpar; >>>>> + opar = oc->streams[i]->codecpar; >>>>> + avcodec_parameters_copy(opar, ipar); >>>>> + if (!oc->oformat->codec_tag || >>>>> + av_codec_get_id (oc->oformat->codec_tag, >>> ipar->codec_tag) >>>>> == opar->codec_id || >>>>> + av_codec_get_tag(oc->oformat->codec_tag, >>> ipar->codec_id) >>>>> <= 0) { >>>>> + opar->codec_tag = ipar->codec_tag; >>>>> + } else { >>>>> + opar->codec_tag = 0; >>>>> + } >>>>> + st->sample_aspect_ratio = s->streams[i]->sample_aspect_r >>> atio; >>>>> + st->time_base = s->streams[i]->time_base; >>>>> + } >>>>> ret = avformat_write_header(oc, NULL); >>>>> if (ret < 0) >>>>> return ret; >>>>> @@ -978,6 +995,25 @@ fail: >>>>> return ret; >>>>> } >>>>> >>>>> +static int seg_check_bitstream(struct AVFormatContext *s, const >>> AVPacket >>>>> *pkt) >>>>> +{ >>>>> + SegmentContext *seg = s->priv_data; >>>>> + AVFormatContext *oc = seg->avf; >>>>> + if (oc->oformat->check_bitstream) { >>>>> + int ret = oc->oformat->check_bitstream(oc, pkt); >>>>> + if (ret == 1) { >>>>> + AVStream *st = s->streams[pkt->stream_index]; >>>>> + AVStream *ost = oc->streams[pkt->stream_index]; >>>>> + st->internal->bsfcs = ost->internal->bsfcs; >>>>> + st->internal->nb_bsfcs = ost->internal->nb_bsfcs; >>>>> + ost->internal->bsfcs = NULL; >>>>> + ost->internal->nb_bsfcs = 0; >>>>> + } >>>>> + return ret; >>>>> + } >>>>> + return 1; >>>>> +} >>>>> + >>>>> #define OFFSET(x) offsetof(SegmentContext, x) >>>>> #define E AV_OPT_FLAG_ENCODING_PARAM >>>>> static const AVOption options[] = { >>>>> @@ -1041,6 +1077,7 @@ AVOutputFormat ff_segment_muxer = { >>>>> .write_packet = seg_write_packet, >>>>> .write_trailer = seg_write_trailer, >>>>> .deinit = seg_free, >>>>> + .check_bitstream = seg_check_bitstream, >>>>> .priv_class = &seg_class, >>>>> }; >>>>> >>>>> @@ -1061,5 +1098,6 @@ AVOutputFormat ff_stream_segment_muxer = { >>>>> .write_packet = seg_write_packet, >>>>> .write_trailer = seg_write_trailer, >>>>> .deinit = seg_free, >>>>> + .check_bitstream = seg_check_bitstream, >>>>> .priv_class = &sseg_class, >>>>> }; >>>>> -- >>>>> 2.10.0 >>>>> >>>>> _______________________________________________ >>>>> ffmpeg-devel mailing list >>>>> ffmpeg-devel@ffmpeg.org >>>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel >>>> >>>> >>>> This is move to usual area by Michael >>>> you can refer to commit id: e29d2d9c92e19b0caf05a2064d132ccdecdfc3d5 >>>> and >>>> de9674c5eacc076894bd0f94bee0001ba6ab8344 >>> >>> See 45f5c5573203a48acb2dd6fbf18f4b0c25b7aff0 (which accidentally breaks >>> autobsf for segment [patch was written before e29d2d9c92e19b0caf05a2064d132c >>> cdecdfc3d5]). >>> This is necessary for the separate-header-file functionality to work. >>> >> refer to http://ffmpeg.org/pipermail/ffmpeg-devel/2016-June/196016.html >> >>> >>>> _______________________________________________ >>>> ffmpeg-devel mailing list >>>> ffmpeg-devel@ffmpeg.org >>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel >>> >>> _______________________________________________ >>> ffmpeg-devel mailing list >>> ffmpeg-devel@ffmpeg.org >>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel >>> >> > > Maybe we should re-factor this BSF logic into a shareable function and > make both av_write_frame and av_interleaved_write_frame use it then, > instead of adding it to hlsenc (and after that even more > playlist-muxers like dash, segment, etc) > > > - Said by Hendrik Leppkes > I think Hendrik Leppkes is right, and same here
The point is that when writing the header to a separate file (using the segment_header_filename option), we can't rely on the underlying muxer using auto-bsf. Since auto-bsf delays calling write_header until the first packet of each stream is written, we'd end up with an empty header file, with the header data being written into the first segment. > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org <mailto:ffmpeg-devel@ffmpeg.org> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > <http://ffmpeg.org/mailman/listinfo/ffmpeg-devel> _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
