Re: [Alsa-devel] Rate Conversion
Paul Davis wrote: You don't need to do this. Use the 'plughw' device which should do all conversions from you. I am a little confused about your advice. I am not sure how to access the 'plughw' device from my application. snd_pcm_open (handle, plughw:N,M, ...) where N and M are the card number and subdevice number. Preferably, this is a string supplied by the user, not hard coded into the application. I am not sure of how I should be setting up my PCM devices. How do I tell them to convert, say, 8kHz audio data to 44.1kHz audio data so my hardware can play it at the correct speed? just as in the few token API examples. using snd_pcm_hw_params_*(). there is no difference setting the parameters no matter what type of PCM device you are using. If use the virtual plughw:0,0 device and set the rate to 8kHz, at what rate is my actual hardware device set to? Where are these settings made and how are they decided? Do I need to, or is it possible to, tell my soundcard to operate at 44.1kHz? Kris Modrak --- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] Rate Conversion
Jaroslav Kysela wrote: On Thu, 27 Jun 2002, Kris Modrak wrote: I am writing a PCM application and wish to play a .wav file that has a sampling rate of 8kHz on a hardware setup that only supports sampling frequencies of 44.1 or 48kHz. Does anyone know how to implement this? You don't need to do this. Use the 'plughw' device which should do all conversions from you. I am a little confused about your advice. I am not sure how to access the 'plughw' device from my application. I have a full duplex application that can play a file at 44.1kHz and record at the same rate but I want it to operate at lower sampling frequencies. I am not sure of how I should be setting up my PCM devices. How do I tell them to convert, say, 8kHz audio data to 44.1kHz audio data so my hardware can play it at the correct speed? I tried using aplay with plughw to play an 8kHz file and got the following results aplay -Dplughw s1.wav Playing WAVE 's1.wav' : Signed 16 bit Little Endian, Rate 8000 Hz, Mono Segmentation fault However it worked when using a 441.kHz file. Regards Kris Modrak --- This sf.net email is sponsored by:ThinkGeek Bringing you mounds of caffeinated joy. http://thinkgeek.com/sf ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
