as far as I know: sample format S24_LE is 24bit sample in 4 bytes sample format S24_3LE is 24bit sample in 3 bytes (why else have separate definitions), right ? In the ALSA-LIb example /test/pcm.c however (http://www.alsa-project.org/alsa-doc/alsa-lib/_2test_2pcm_8c-example.html) there is no diff between the 2 sample formats. I noticed this by simply showing the bytes presented to snd_pcm_writei See: S32_LE (for reference) ---------------------- ./pcm -c 2 -o S32_LE -f 4000 Playback device is plughw:0,0 Stream parameters are 48000Hz, S32_LE, 2 channels Sine wave rate is 4000.0000Hz Using transfer method: write write_loop: going to write: period_size=4096 samples data[00:31]= 00000000 00000000 ffffff3f ffffff3f a0ebd96e a0ebd96e ffffff7f ffffff7f data[32:63]= a0ebd96e a0ebd96e ffffff3f ffffff3f 00000000 00000000 010000c0 010000c0 S24_3LE (as expected) ---------------------- ./pcm -c 2 -o S24_3LE -f 4000 Playback device is plughw:0,0 Stream parameters are 48000Hz, S24_3LE, 2 channels Sine wave rate is 4000.0000Hz Using transfer method: write write_loop: going to write: period_size=4096 samples data[00:31]= 00000000 0000ffff 3fffff3f ead96eea d96effff 7fffff7f ead96eea d96effff data[32:63]= 3fffff3f 00000000 00000100 c00100c0 16269116 26910100 80010080 16269116 S24_LE ---------------------- ./pcm -c 2 -o S24_LE -f 4000 Playback device is plughw:0,0 Stream parameters are 48000Hz, S24_LE, 2 channels Sine wave rate is 4000.0000Hz Using transfer method: write write_loop: going to write: period_size=4096 samples data[00:31]= 00000000 0000ffff 3fffff3f ead96eea d96effff 7fffff7f ead96eea d96effff data[32:63]= 3fffff3f 00000000 00000100 c00100c0 16269116 26910100 80010080 16269116 I would expect to see data[00:31]= 0x00000000 00000000 00ffff3f 00ffff3f 00ebd96e 00ebd96e 00ffff7f 00ffff7f data[32:63]= 0x00ebd96e 00ebd96e 00ffff3f 00ffff3f 00000000 00000000 000000c0 000000c0 for S24_LE do I miss something ? is this is a fault in /test/pcm.c ? -- This message has been scanned for viruses and is believed to be clean ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
