Paul Braman wrote: > Data is broken up on an S/PDIF stream into 64-bit frames grouped into > 192-frame blocks (1536-byte blocks). Assuming I can properly decode > all of the status bits in each frame, blah blah blah, I can end up > with either a PCM stream or, let's say, a compressed-audio stream > consisting of AC-3 to DTS bitstream data. (For example, I might be > recording the output of a DVD player.) > > Once I have the specific information about what to do with the > bitstream (either record it directly to file if it's PCM or run it > through a decoder if it's AC-3 or DTS), I'm golden. The problem somes > in my trying to figure out the proper way to open a device and record > the output so I can do whatever it is I need to do. Almost all sound cards decode the S/PDIF stream; what you get are plain samples (or compressed data pretending to be samples in case of AC-3 or DTS). The information in the other bits is usually available with the control "IEC958 Capture Default". The only exception is the CMI8738 which can capture (and must play) S/PDIF data as raw 32-bit subframes; the format SND_PCM_FORMAT_IEC958_SUBFRAME is not understood by any application, but ALSA can convert it to something useful.) Regards, Clemens ------------------------------------------------------------------------------ Nokia and AT&T present the 2010 Calling All Innovators-North America contest Create new apps & games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
