ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinha...@gmail.com> | Wed Jan 22 18:45:08 2020 +0100| [0fc150f048398c9dbb8578f25e916fd356c18a54] | committer: Andreas Rheinhardt
avformat/matroskaenc: Remove unnecessary avio_tell(), avio_seek() avio_close_dyn_buf() has a bug: When the write pointer does not point to the end of the written data when calling it (i.e. when one has performed a seek back to update already written data), it would not add padding to the end of the buffer, but to the current position, overwriting other data; furthermore the reported size would be wrong (off by the amount of data it has overwritten with padding). In order not to run into this when updating already written elements or elements for which size has only been reserved, the Matroska muxer would first record the current position of the dynamic buffer, then seek to the desired position, perform the update and seek back to the earlier position. But now that end_ebml_master_crc32() does not make use of avio_close_dyn_buf() any more, this is no longer necessary. Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0fc150f048398c9dbb8578f25e916fd356c18a54 --- libavformat/matroskaenc.c | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c index f833fda14c..223406ce75 100644 --- a/libavformat/matroskaenc.c +++ b/libavformat/matroskaenc.c @@ -2182,7 +2182,6 @@ static int mkv_check_new_extra_data(AVFormatContext *s, AVPacket *pkt) case AV_CODEC_ID_AAC: if (side_data_size && (s->pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live) { int filler, output_sample_rate = 0; - int64_t curpos; ret = get_aac_sample_rates(s, side_data, side_data_size, &track->sample_rate, &output_sample_rate); if (ret < 0) @@ -2193,7 +2192,6 @@ static int mkv_check_new_extra_data(AVFormatContext *s, AVPacket *pkt) if (ret < 0) return ret; memcpy(par->extradata, side_data, side_data_size); - curpos = avio_tell(mkv->tracks_bc); avio_seek(mkv->tracks_bc, track->codecpriv_offset, SEEK_SET); mkv_write_codecprivate(s, mkv->tracks_bc, par, 1, 0); filler = MAX_PCE_SIZE + 2 + 4 - (avio_tell(mkv->tracks_bc) - track->codecpriv_offset); @@ -2202,7 +2200,6 @@ static int mkv_check_new_extra_data(AVFormatContext *s, AVPacket *pkt) avio_seek(mkv->tracks_bc, track->sample_rate_offset, SEEK_SET); put_ebml_float(mkv->tracks_bc, MATROSKA_ID_AUDIOSAMPLINGFREQ, track->sample_rate); put_ebml_float(mkv->tracks_bc, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate); - avio_seek(mkv->tracks_bc, curpos, SEEK_SET); } else if (!par->extradata_size && !track->sample_rate) { // No extradata (codecpar or packet side data). av_log(s, AV_LOG_ERROR, "Error parsing AAC extradata, unable to determine samplerate.\n"); @@ -2212,7 +2209,6 @@ static int mkv_check_new_extra_data(AVFormatContext *s, AVPacket *pkt) case AV_CODEC_ID_FLAC: if (side_data_size && (s->pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live) { AVCodecParameters *codecpriv_par; - int64_t curpos; if (side_data_size != par->extradata_size) { av_log(s, AV_LOG_ERROR, "Invalid FLAC STREAMINFO metadata for output stream %d\n", pkt->stream_index); @@ -2227,10 +2223,8 @@ static int mkv_check_new_extra_data(AVFormatContext *s, AVPacket *pkt) return ret; } memcpy(codecpriv_par->extradata, side_data, side_data_size); - curpos = avio_tell(mkv->tracks_bc); avio_seek(mkv->tracks_bc, track->codecpriv_offset, SEEK_SET); mkv_write_codecprivate(s, mkv->tracks_bc, codecpriv_par, 1, 0); - avio_seek(mkv->tracks_bc, curpos, SEEK_SET); avcodec_parameters_free(&codecpriv_par); } break; @@ -2242,7 +2236,6 @@ static int mkv_check_new_extra_data(AVFormatContext *s, AVPacket *pkt) AVIOContext *dyn_cp; uint8_t *codecpriv; int codecpriv_size; - int64_t curpos; ret = avio_open_dyn_buf(&dyn_cp); if (ret < 0) return ret; @@ -2252,12 +2245,10 @@ static int mkv_check_new_extra_data(AVFormatContext *s, AVPacket *pkt) av_free(codecpriv); return AVERROR_INVALIDDATA; } - curpos = avio_tell(mkv->tracks_bc); avio_seek(mkv->tracks_bc, track->codecpriv_offset, SEEK_SET); // Do not write the OBUs as we don't have space saved for them put_ebml_binary(mkv->tracks_bc, MATROSKA_ID_CODECPRIVATE, codecpriv, 4); av_free(codecpriv); - avio_seek(mkv->tracks_bc, curpos, SEEK_SET); ret = ff_alloc_extradata(par, side_data_size); if (ret < 0) return ret; @@ -2556,7 +2547,6 @@ static int mkv_write_trailer(AVFormatContext *s) // update stream durations if (!mkv->is_live) { int i; - int64_t curr = avio_tell(mkv->tags_bc); for (i = 0; i < s->nb_streams; ++i) { AVStream *st = s->streams[i]; mkv_track *track = &mkv->tracks[i]; @@ -2577,7 +2567,6 @@ static int mkv_write_trailer(AVFormatContext *s) put_ebml_binary(mkv->tags_bc, MATROSKA_ID_TAGSTRING, duration_string, 20); } } - avio_seek(mkv->tags_bc, curr, SEEK_SET); } if (mkv->tags_bc && !mkv->is_live) { avio_seek(pb, mkv->tags_pos, SEEK_SET); _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
