ffmpeg | branch: master | Jan Ekström <jee...@gmail.com> | Sun Sep 20 14:41:18 2020 +0300| [667d5045d38c19a9a7ccfe7f1abaaf4cb8b225fc] | committer: Jan Ekström
avformat/movenc: split MPEG-4 bit rate value calculation This can now be re-utilized in other places. > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=667d5045d38c19a9a7ccfe7f1abaaf4cb8b225fc --- libavformat/movenc.c | 44 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 34 insertions(+), 10 deletions(-) diff --git a/libavformat/movenc.c b/libavformat/movenc.c index 12471c7d68..5888d10770 100644 --- a/libavformat/movenc.c +++ b/libavformat/movenc.c @@ -633,12 +633,41 @@ static unsigned compute_avg_bitrate(MOVTrack *track) return size * 8 * track->timescale / track->track_duration; } +struct mpeg4_bit_rate_values { + uint32_t buffer_size; ///< Size of the decoding buffer for the elementary stream in bytes. + uint32_t max_bit_rate; ///< Maximum rate in bits/second over any window of one second. + uint32_t avg_bit_rate; ///< Average rate in bits/second over the entire presentation. +}; + +static struct mpeg4_bit_rate_values calculate_mpeg4_bit_rates(MOVTrack *track) +{ + AVCPBProperties *props = + (AVCPBProperties*)av_stream_get_side_data(track->st, + AV_PKT_DATA_CPB_PROPERTIES, + NULL); + struct mpeg4_bit_rate_values bit_rates = { 0 }; + + bit_rates.avg_bit_rate = compute_avg_bitrate(track); + + // (FIXME should be max rate in any 1 sec window) + bit_rates.max_bit_rate = FFMAX(track->par->bit_rate, + bit_rates.avg_bit_rate); + + // utilize values from properties if we have them available + if (props) { + bit_rates.max_bit_rate = FFMAX(bit_rates.max_bit_rate, + props->max_bitrate); + bit_rates.buffer_size = props->buffer_size / 8; + } + + return bit_rates; +} + static int mov_write_esds_tag(AVIOContext *pb, MOVTrack *track) // Basic { - AVCPBProperties *props; + struct mpeg4_bit_rate_values bit_rates = calculate_mpeg4_bit_rates(track); int64_t pos = avio_tell(pb); int decoder_specific_info_len = track->vos_len ? 5 + track->vos_len : 0; - unsigned avg_bitrate; avio_wb32(pb, 0); // size ffio_wfourcc(pb, "esds"); @@ -669,14 +698,9 @@ static int mov_write_esds_tag(AVIOContext *pb, MOVTrack *track) // Basic else avio_w8(pb, 0x11); // flags (= Visualstream) - props = (AVCPBProperties*)av_stream_get_side_data(track->st, AV_PKT_DATA_CPB_PROPERTIES, - NULL); - - avio_wb24(pb, props ? props->buffer_size / 8 : 0); // Buffersize DB - - avg_bitrate = compute_avg_bitrate(track); - avio_wb32(pb, props ? FFMAX3(props->max_bitrate, props->avg_bitrate, avg_bitrate) : FFMAX(track->par->bit_rate, avg_bitrate)); // maxbitrate (FIXME should be max rate in any 1 sec window) - avio_wb32(pb, avg_bitrate); + avio_wb24(pb, bit_rates.buffer_size); // Buffersize DB + avio_wb32(pb, bit_rates.max_bit_rate); // maxbitrate + avio_wb32(pb, bit_rates.avg_bit_rate); if (track->vos_len) { // DecoderSpecific info descriptor _______________________________________________ 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".
