Hi Shengjiu,
On 21/03/2024 15:57, Mauro Carvalho Chehab wrote:
> Em Tue, 19 Mar 2024 16:15:35 +0100
> Hans Verkuil <hverkuil@xxxxxxxxx> escreveu:
>
>> Hi Mauro,
>>
>> This adds support for the imx-asrc m2m audio rate control driver. Most of these
>> patches add support for the new v4l-audioX device nodes and related types,
>> and adding support for fixed point control types.
>>
>> The ASoC patches have been acked by Mark Brown.
>>
>> It also adds a vim2m-audio test driver so we can test the v4l-audio infrastructure.
>>
>> Since V4L2 is fourcc-based all the way, directly using snd_pcm_format_t values
>> is not an option: fourcc's are expected to be printable characters, and it is
>> pretty much certain that there are applications that show it like that to the
>> end-user. The utilities in v4l-utils certainly do, and it is in fact a
>> perfectly reasonable thing to do. So instead we map the snd_pcm_format_t value
>> to a fourcc with v4l2_audfmt_to_fourcc and map it back with v4l2_fourcc_to_audfmt.
>
> I still think that this can cause maintenance burden to sync up changes
> from fourcc to snd_pcm_format_t for no good reason, as any apps that will
> be working with this will require changes anyway to support the new
> devnodes and ioctls.
I will need more time to dig into this. I was on vacation for over a week, and
after that I was very busy. This needs more time from me.
But I haven't forgotten this, and it is on my todo list!
Regards,
Hans
>
> With regards to printable fourcc values, it doesn't seem the best for audio.
> I mean, for V4L2, when we had fourcc introduced, the formats were:
>
> RGB3
> BGR3
> YUYV
> ...
>
> so, just printing them as ASCII would make sense, but those days were
> gone a very long time ago, as now we have fourccs like:
>
> pBCC
>
> Which you can't really know what it means, except by looking on its
> definition:
>
> #define V4L2_PIX_FMT_SBGGR12P v4l2_fourcc('p', 'B', 'C', 'C')
>
> For audio, even today's proposal makes no sense to be printed as
> ASCII. See, it is a lot clearer if userspace would print:
>
> "PCM A-LAW" # for ITU-T G711 A-law 8-bit encoding
> "PCM μ-LAW" # for ITU-T G711 μ-law 8-bit encoding
> "PCM S8" # for low-quality s8 encoding
> ...
> "PCM S32_LE"
> ...
>
> than any obfuscated fourccs:
>
> "AUAL" # currently missing at V4L2 proposal patch
> "AUML" # currently missing at V4L2 proposal patch
> "AU00"
> ...
> "AU10"
> ...
>
> Besides that, there were never any warranty that fourccs are printable
> at the media subsystem. I might be wrong but I guess we even used some
> unprintable ones in the past.
>
>
> So, the argument that new apps that will support audio will need to
> receive a fourcc instead of snd_pcm_format_t sounds bogus to me.
>
> Also, the current proposal misses lots of already-existing codes at
> snd_pcm_format_t.
>
>
>>
>> This PR is using v15 of the patch series:
>>
>> https://patchwork.linuxtv.org/project/linux-media/list/?series=12460
>>
>> And the corresponding v4l-utils patch series is here:
>>
>> https://patchwork.linuxtv.org/user/todo/linux-media/?series=12074
>>
>> Regards,
>>
>> Hans
>>
>> The following changes since commit b14257abe7057def6127f6fb2f14f9adc8acabdb:
>>
>> media: rcar-isp: Disallow unbind of devices (2024-03-07 16:35:13 +0100)
>>
>> are available in the Git repository at:
>>
>> git://linuxtv.org/hverkuil/media_tree.git tags/br-audio
>>
>> for you to fetch changes up to af06c8792653c42d1f126505ec9180255091d94e:
>>
>> media: vim2m-audio: add virtual driver for audio memory to memory (2024-03-19 15:55:38 +0100)
>>
>> ----------------------------------------------------------------
>> Tag branch
>>
>> ----------------------------------------------------------------
>> Hans Verkuil (1):
>> media: v4l2-ctrls: add support for fraction_bits
>>
>> Shengjiu Wang (15):
>> ASoC: fsl_asrc: define functions for memory to memory usage
>> ASoC: fsl_easrc: define functions for memory to memory usage
>> ASoC: fsl_asrc: move fsl_asrc_common.h to include/sound
>> ASoC: fsl_asrc: register m2m platform device
>> ASoC: fsl_easrc: register m2m platform device
>> media: uapi: Add V4L2_CAP_AUDIO_M2M capability flag
>> media: v4l2: Add audio capture and output support
>> media: uapi: Define audio sample format fourcc type
>> media: uapi: Add V4L2_CTRL_CLASS_M2M_AUDIO
>> media: uapi: Add audio rate controls support
>> media: uapi: Declare interface types for Audio
>> media: uapi: Add an entity type for audio resampler
>> media: vivid: add fixed point test controls
>> media: imx-asrc: Add memory to memory driver
>> media: vim2m-audio: add virtual driver for audio memory to memory
>>
>> Documentation/userspace-api/media/mediactl/media-types.rst | 11 +
>> Documentation/userspace-api/media/v4l/buffer.rst | 6 +
>> Documentation/userspace-api/media/v4l/common.rst | 1 +
>> Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst | 71 +++
>> Documentation/userspace-api/media/v4l/devices.rst | 1 +
>> Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst | 59 +++
>> Documentation/userspace-api/media/v4l/pixfmt-audio.rst | 100 ++++
>> Documentation/userspace-api/media/v4l/pixfmt.rst | 1 +
>> Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst | 2 +
>> Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst | 4 +
>> Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst | 4 +
>> Documentation/userspace-api/media/v4l/vidioc-querycap.rst | 3 +
>> Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst | 11 +-
>> Documentation/userspace-api/media/videodev2.h.rst.exceptions | 3 +
>> MAINTAINERS | 17 +
>> drivers/media/common/videobuf2/videobuf2-v4l2.c | 4 +
>> drivers/media/platform/nxp/Kconfig | 13 +
>> drivers/media/platform/nxp/Makefile | 1 +
>> drivers/media/platform/nxp/imx-asrc.c | 1256 +++++++++++++++++++++++++++++++++++++++++++++++++++
>> drivers/media/test-drivers/Kconfig | 10 +
>> drivers/media/test-drivers/Makefile | 1 +
>> drivers/media/test-drivers/vim2m-audio.c | 793 ++++++++++++++++++++++++++++++++
>> drivers/media/test-drivers/vivid/vivid-core.h | 2 +
>> drivers/media/test-drivers/vivid/vivid-ctrls.c | 26 ++
>> drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +
>> drivers/media/v4l2-core/v4l2-ctrls-api.c | 1 +
>> drivers/media/v4l2-core/v4l2-ctrls-core.c | 93 +++-
>> drivers/media/v4l2-core/v4l2-ctrls-defs.c | 10 +
>> drivers/media/v4l2-core/v4l2-dev.c | 21 +
>> drivers/media/v4l2-core/v4l2-ioctl.c | 66 +++
>> drivers/media/v4l2-core/v4l2-mem2mem.c | 13 +-
>> include/media/v4l2-ctrls.h | 13 +-
>> include/media/v4l2-dev.h | 2 +
>> include/media/v4l2-ioctl.h | 34 ++
>> {sound/soc/fsl => include/sound}/fsl_asrc_common.h | 60 +++
>> include/uapi/linux/media.h | 2 +
>> include/uapi/linux/v4l2-controls.h | 9 +
>> include/uapi/linux/videodev2.h | 50 +-
>> sound/soc/fsl/fsl_asrc.c | 144 ++++++
>> sound/soc/fsl/fsl_asrc.h | 4 +-
>> sound/soc/fsl/fsl_asrc_dma.c | 2 +-
>> sound/soc/fsl/fsl_easrc.c | 233 ++++++++++
>> sound/soc/fsl/fsl_easrc.h | 6 +-
>> 43 files changed, 3145 insertions(+), 27 deletions(-)
>> create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
>> create mode 100644 Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
>> create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-audio.rst
>> create mode 100644 drivers/media/platform/nxp/imx-asrc.c
>> create mode 100644 drivers/media/test-drivers/vim2m-audio.c
>> rename {sound/soc/fsl => include/sound}/fsl_asrc_common.h (60%)
>>
>
