On Wed, 02 Aug 2023 14:02:29 +0200, Shengjiu Wang wrote: > > On Wed, Aug 2, 2023 at 7:22 PM Takashi Iwai <tiwai@xxxxxxx> wrote: > > > > On Wed, 02 Aug 2023 09:32:37 +0200, > > Hans Verkuil wrote: > > > > > > Hi all, > > > > > > On 25/07/2023 08:12, Shengjiu Wang wrote: > > > > Audio signal processing has the requirement for memory to > > > > memory similar as Video. > > > > > > > > This patch is to add this support in v4l2 framework, defined > > > > new buffer type V4L2_BUF_TYPE_AUDIO_CAPTURE and > > > > V4L2_BUF_TYPE_AUDIO_OUTPUT, defined new format v4l2_audio_format > > > > for audio case usage. > > > > > > > > The created audio device is named "/dev/audioX". > > > > > > > > And add memory to memory support for two kinds of i.MX ASRC > > > > module > > > > > > Before I spend time on this: are the audio maintainers OK with doing > > > this in V4L2? > > > > > > I do want to have a clear statement on this as it is not something I > > > can decide. > > > > Well, I personally don't mind to have some audio capability in v4l2 > > layer. But, the only uncertain thing for now is whether this is a > > must-have or not. > > > > Thanks, I am also not sure about this. I am also confused that why > there is no m2m implementation for audio in the kernel. Audio also > has similar decoder encoder post-processing as video. > > > > > IIRC, the implementation in the sound driver side was never done just > > because there was no similar implementation? If so, and if the > > extension to the v4l2 core layer is needed, shouldn't it be more > > considered for the possible other route? > > > > Actually I'd like someone could point me to the other route. I'd like to > try. > > The reason why I select to extend v4l2 for such audio usage is that v4l2 > looks best for this audio m2m implementation. v4l2 is designed for m2m > usage. if we need implement another 'route', I don't think it can do better > that v4l2. > > I appreciate that someone can share his ideas or doable solutions. > And please don't ignore my request, ignore my patch. Can you explain a bit more details of your demand? At least, a "big picture" showing how your hardware is implemented and what is exactly necessary would be helpful for understanding the problem. thanks, Takashi