At Tue, 17 Jul 2007 12:33:36 +0100, Alan Horstmann wrote:
On Monday 16 July 2007 13:30, you wrote:
At Mon, 16 Jul 2007 13:40:23 +0100,
Alan Horstmann wrote:
Quick questions:
- Does SALSA provide everything needed by aplay?
Most but not everything. The missing features are:
- snd_pcm_mmap_read*/write*() (corresponding to -M option)
- device listing (namehint)
Thanks. Presumably that explains 'undeclared' error for 'snd_devname_t' and 'snd_config' when linking aplay code to salsa. I commented out all applicable bits and it is OK.
Can salsa-lib be installed at the same time as alsa-lib? There seems to be conflicts. For now I have uninstalled and installed alternately.
For the runtime environment, yes, but not for the development since both salsa and alsa-lib use the same header file location. But, in principle, it doesn't make much sense to use salsa-lib where alsa-lib is available and needed.
I have very crudely hacked the aplay code and included it as a function in code to make a simple key-press play a set file. Linking -lasound this seems to work fine. However, linking -lsalsa results in the file playing too fast, but not as much as double.
Probably you are playing the samples with the hardware parameters that the hardware doesn't support. alsa-lib has plugin layer which can convert appropriatley on the fly.
As my experimental system has ice1712 card, I am having to use a 10 track WAV file S32_LE as I think that is the only format supported, the card working with 24-bits loose fitted in 32-bits. Is that right?
Yes.
Is there still something that alsa-lib is doing to the data that salsa doesn't? My example wav file was recorded using standard aplay, and has meaningful sound just on the first 4 tracks, which appear correctly in pcm out 1-4 (visible in envy24control), at the correct level, just too fast. The included aplay correctly reports
try3.wav' : Signed 32 bit Little Endian, Rate 44100 Hz, Channels 10
when begining to play.
ice1712 always requires 10-channel interleaved format, regardless how many physical I/O the device has.
Takashi