Hi, Thanks for your immediate reply.

My hardware supports MP3 decoding in HW (in addition to few others). I am looking to write a driver such that when an MP3 file is played, the file is decoded using the HW decoder and played. Is there a possibility in current ALSA framework to do so?

Thanks, Harsha.

On Mon, Feb 25, 2008 at 5:33 PM, Takashi Iwai tiwai@suse.de wrote:

At Mon, 25 Feb 2008 12:27:00 +0530, Harsha priya gupta wrote:

...

Hi,

I am new to ALSA and audio stack in Linux. I have a sound card that can

do

...

HW decoding as well. I am looking at writing an ALSA driver such that whatever may be the player or MMF above, it should use the HW decoder

and

...

not the inherit SW decoder that is available with the player.

Can someone help me with some pointers or existing like-drivers?

Which format is in mind? In theoery, you can implement the h/w decoder on the ALSA framework, but there are some restrictions:

• ALSA PCM assumes the constant bitrate
• The format bit must be defined
• The specific app recognizes and supports that format

In the case of AC3 or DTS, it's embedded in SPDIF frames so the PCM core stuff doesn't take care of the above. But, in the case of native (non-PCM) formats, the support can be difficult as is.

Takashi