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| author | Marton Balint <cus@passwd.hu> | 2024-02-26 01:12:23 +0100 |
|---|---|---|
| committer | Marton Balint <cus@passwd.hu> | 2024-03-02 19:13:03 +0100 |
| commit | 3a09c2122d1f77c3e14c43855b21ef1da9f7fa27 (patch) | |
| tree | 49b9ae5fd6d5006f3724d9185604cd590f737f1e /libavformat | |
| parent | 315be8b27926fb46338a8fc10cf39cbb9f99dcc8 (diff) | |
| download | ffmpeg-3a09c2122d1f77c3e14c43855b21ef1da9f7fa27.tar.gz | |
avformat/wavdec: dynamically set max_size by default
The wav demuxer by default tried to demux 4096-byte packets which caused
packets with very few number of samples for files with high channel count.
This caused a significant overhead especially since the latest ffmpeg.c
threading changes.
So let's use a similar approach for selecting audio frame size which is already
used in the PCM demuxer, which is to read 25 times per second but at most 1024
samples.
Signed-off-by: Marton Balint <cus@passwd.hu>
Diffstat (limited to 'libavformat')
| -rw-r--r-- | libavformat/wavdec.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/libavformat/wavdec.c b/libavformat/wavdec.c index 0c6629b157..5ceb8bef23 100644 --- a/libavformat/wavdec.c +++ b/libavformat/wavdec.c @@ -73,10 +73,25 @@ static const AVOption demux_options[] = { #if CONFIG_WAV_DEMUXER { "ignore_length", "Ignore length", OFFSET(ignore_length), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, DEC }, #endif - { "max_size", "max size of single packet", OFFSET(max_size), AV_OPT_TYPE_INT, { .i64 = 4096 }, 1024, 1 << 22, DEC }, + { "max_size", "max size of single packet", OFFSET(max_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1 << 22, DEC }, { NULL }, }; +static void set_max_size(AVStream *st, WAVDemuxContext *wav) +{ + if (wav->max_size <= 0) { + int64_t nb_samples = av_clip(st->codecpar->sample_rate / 25, 1, 1024); + if (st->codecpar->block_align > 0 && + st->codecpar->block_align * nb_samples < INT_MAX && + st->codecpar->ch_layout.nb_channels > 0 && + st->codecpar->block_align <= 8LL * st->codecpar->ch_layout.nb_channels) { + wav->max_size = st->codecpar->block_align * nb_samples; + } else { + wav->max_size = 4096; + } + } +} + static void set_spdif(AVFormatContext *s, WAVDemuxContext *wav) { if (CONFIG_SPDIF_DEMUXER && s->streams[0]->codecpar->codec_tag == 1) { @@ -669,6 +684,7 @@ break_loop: ff_metadata_conv_ctx(s, NULL, ff_riff_info_conv); set_spdif(s, wav); + set_max_size(st, wav); return 0; } @@ -981,6 +997,7 @@ static int w64_read_header(AVFormatContext *s) avio_seek(pb, data_ofs, SEEK_SET); set_spdif(s, wav); + set_max_size(st, wav); return 0; } |