Hi, The attached patch fixes incorrect bit rate values in riff headers when a conversion is done from 16 bit samples to alaw.
[user@test ffmpeg-new]$ ./ffprobe ../sample.wav 2>&1 | tail -4
Input #0, wav, from '../sample.wav':
Duration: 00:00:10.00, bitrate: 256 kb/s
Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 16000 Hz, 1
channels, s16, 256 kb/s
[user@test ffmpeg-new]$ ./ffmpeg -i ../sample.wav -f wav -acodec pcm_alaw -ac 1
-ar 8000 ../sample.alaw.wav
ffmpeg version 0.10.14 Copyright (c) 2000-2014 the FFmpeg developers
built on Aug 12 2014 12:30:33 with gcc 4.1.2 20080704 (Red Hat 4.1.2-51)
configuration: --disable-yasm
libavutil 51. 35.100 / 51. 35.100
libavcodec 53. 61.100 / 53. 61.100
libavformat 53. 32.100 / 53. 32.100
libavdevice 53. 4.100 / 53. 4.100
libavfilter 2. 61.100 / 2. 61.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 6.100 / 0. 6.100
[wav @ 0x158813a0] max_analyze_duration 5000000 reached at 5120000
Input #0, wav, from '../sample.wav':
Duration: 00:00:10.00, bitrate: 256 kb/s
Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 16000 Hz, 1
channels, s16, 256 kb/s
File '../sample.alaw.wav' already exists. Overwrite ? [y/N] y
Output #0, wav, to '../sample.alaw.wav':
Metadata:
encoder : Lavf53.32.100
Stream #0:0: Audio: pcm_alaw ([6][0][0][0] / 0x0006), 8000 Hz, 1 channels,
s 16, 64 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (pcm_s16le -> pcm_alaw)
Press [q] to stop, [?] for help
size= 78kB time=00:00:09.99 bitrate= 64.0kbits/s
video:0kB audio:78kB global headers:0kB muxing overhead 0.072509%
[user@test ffmpeg-new]$ ./ffprobe ../sample.alaw.wav 2>&1 | tail -4
Input #0, wav, from '../sample.alaw.wav':
Duration: 00:00:09.99, bitrate: 64 kb/s
Stream #0:0: Audio: pcm_alaw ([6][0][0][0] / 0x0006), 8000 Hz, 1 channels,
s 16, 64 kb/s
Without the patch ffprobe would report a bit rate of 128kb/s.
Greetings,
Wilfried
0001-merge-pcmenc-set-correct-bitrate-value.patch
Description: 0001-merge-pcmenc-set-correct-bitrate-value.patch
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
