[FFmpeg-trac] #9594(avcodec:new): alac encoder does no support 20bits depth
FFmpeg
trac at avcodec.org
Tue Jan 11 05:38:37 EET 2022
#9594: alac encoder does no support 20bits depth
---------------------------------+---------------------------------------
Reporter: Michael | Type: defect
Status: new | Priority: normal
Component: avcodec | Version: unspecified
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
---------------------------------+---------------------------------------
Summary of the bug:
alac decoder support 20 bits bit depth, but encoder does not.
seems fixed bit depth in code of encoder.
libavcodec\alacenc.c
---
if (avctx->sample_fmt == AV_SAMPLE_FMT_S32P) {
if (avctx->bits_per_raw_sample != 24)
av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-
sample\n");
avctx->bits_per_raw_sample = 24;
} else {
avctx->bits_per_raw_sample = 16;
s->extra_bits = 0;
}
---
How to reproduce:
{{{
C:\Data\ffmpeg.exe -i 009.caf -codec alac 009.m4a
ffmpeg version n4.4.1-14-g5a7763bdfa-20220108 Copyright (c) 2000-2021 the
FFmpeg developers
built with gcc 11.2.0 (crosstool-NG 1.24.0.498_5075e1f)
configuration: --prefix=/ffbuild/prefix --pkg-config-flags=--static
--pkg-config=pkg-config --cross-prefix=x86_64-w64-mingw32- --arch=x86_64
--target-os=mingw32 --enable-nonfree --enable-gpl --enable-version3
--disable-debug --enable-shared --disable-static --disable-w32threads
--enable-pthreads --enable-iconv --enable-libxml2 --enable-zlib --enable-
libfreetype --enable-libfribidi --enable-gmp --enable-lzma --enable-
fontconfig --enable-libvorbis --enable-opencl --disable-libpulse --enable-
libvmaf --disable-libxcb --disable-xlib --enable-amf --enable-libaom
--enable-avisynth --enable-libdav1d --enable-libdavs2 --enable-libfdk-aac
--enable-ffnvcodec --enable-cuda-llvm --disable-frei0r --enable-libgme
--enable-libass --enable-libbluray --enable-libmp3lame --enable-libopus
--enable-librist --enable-libtheora --enable-libvpx --enable-libwebp
--enable-lv2 --enable-libmfx --enable-libopencore-amrnb --enable-
libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-
libopenmpt --enable-librav1e --enable-librubberband --enable-schannel
--enable-sdl2 --enable-libsoxr --enable-libsrt --enable-libsvtav1
--enable-libtwolame --enable-libuavs3d --disable-libdrm --disable-vaapi
--enable-libvidstab --disable-vulkan --enable-libx264 --enable-libx265
--enable-libxavs2 --enable-libxvid --enable-libzimg --enable-libzvbi
--extra-cflags=-DLIBTWOLAME_STATIC --extra-cxxflags= --extra-
ldflags=-pthread --extra-ldexeflags= --extra-libs=-lgomp --extra-
version=20220108
libavutil 56. 70.100 / 56. 70.100
libavcodec 58.134.100 / 58.134.100
libavformat 58. 76.100 / 58. 76.100
libavdevice 58. 13.100 / 58. 13.100
libavfilter 7.110.100 / 7.110.100
libswscale 5. 9.100 / 5. 9.100
libswresample 3. 9.100 / 3. 9.100
libpostproc 55. 9.100 / 55. 9.100
Input #0, caf, from '009.caf':
Duration: 00:01:35.02, start: 0.000000, bitrate: 793 kb/s
Stream #0:0: Audio: alac (alac / 0x63616C61), 44100 Hz, stereo, s32p (20
bit), 705 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (alac (native) -> alac (native))
Press [q] to stop, [?] for help
[alac @ 000002e1e6d4f000] encoding as 24 bits-per-sample
Output #0, ipod, to '009.m4a':
Metadata:
encoder : Lavf58.76.100
Stream #0:0: Audio: alac (alac / 0x63616C61), 44100 Hz, stereo, s32p (24
bit), 128 kb/s
Metadata:
encoder : Lavc58.134.100 alac
size= 13663kB time=00:01:34.92 bitrate=1179.2kbits/s speed= 162x
video:0kB audio:13658kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: 0.035743%
}}}
--
Ticket URL: <https://trac.ffmpeg.org/ticket/9594>
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