| Message ID | 1705581128-4604-9-git-send-email-shengjiu.wang@nxp.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add audio support in v4l2 framework | expand |
Em Thu, 18 Jan 2024 20:32:01 +0800 Shengjiu Wang <shengjiu.wang@nxp.com> escreveu: > The audio sample format definition is from alsa, > the header file is include/uapi/sound/asound.h, but > don't include this header file directly, because in > user space, there is another copy in alsa-lib. > There will be conflict in userspace for include > videodev2.h & asound.h and asoundlib.h > > Here still use the fourcc format. > > Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com> > --- > .../userspace-api/media/v4l/pixfmt-audio.rst | 87 +++++++++++++++++++ > .../userspace-api/media/v4l/pixfmt.rst | 1 + > drivers/media/v4l2-core/v4l2-ioctl.c | 13 +++ > include/uapi/linux/videodev2.h | 23 +++++ > 4 files changed, 124 insertions(+) > create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-audio.rst > > diff --git a/Documentation/userspace-api/media/v4l/pixfmt-audio.rst b/Documentation/userspace-api/media/v4l/pixfmt-audio.rst > new file mode 100644 > index 000000000000..04b4a7fbd8f4 > --- /dev/null > +++ b/Documentation/userspace-api/media/v4l/pixfmt-audio.rst > @@ -0,0 +1,87 @@ > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later > + > +.. _pixfmt-audio: > + > +************* > +Audio Formats > +************* > + > +These formats are used for :ref:`audiomem2mem` interface only. > + > +.. tabularcolumns:: |p{5.8cm}|p{1.2cm}|p{10.3cm}| > + > +.. cssclass:: longtable > + > +.. flat-table:: Audio Format > + :header-rows: 1 > + :stub-columns: 0 > + :widths: 3 1 4 > + > + * - Identifier > + - Code > + - Details > + * .. _V4L2-AUDIO-FMT-S8: > + > + - ``V4L2_AUDIO_FMT_S8`` > + - 'S8' > + - Corresponds to SNDRV_PCM_FORMAT_S8 in ALSA > + * .. _V4L2-AUDIO-FMT-S16-LE: Hmm... why can't we just use SNDRV_*_FORMAT_*? Those are already part of an uAPI header. No need to add any abstraction here and/or redefine what is there already at include/uapi/sound/asound.h. Thanks, Mauro
Em Mon, 19 Feb 2024 12:05:02 +0800 Shengjiu Wang <shengjiu.wang@gmail.com> escreveu: > Hi Mauro > > On Sat, Feb 17, 2024 at 5:19 PM Mauro Carvalho Chehab > <mchehab@kernel.org> wrote: > > > > Em Thu, 18 Jan 2024 20:32:01 +0800 > > Shengjiu Wang <shengjiu.wang@nxp.com> escreveu: > > > > > The audio sample format definition is from alsa, > > > the header file is include/uapi/sound/asound.h, but > > > don't include this header file directly, because in > > > user space, there is another copy in alsa-lib. > > > There will be conflict in userspace for include > > > videodev2.h & asound.h and asoundlib.h > > > > > > Here still use the fourcc format. > > > > > > Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com> > > > --- > > > .../userspace-api/media/v4l/pixfmt-audio.rst | 87 +++++++++++++++++++ > > > .../userspace-api/media/v4l/pixfmt.rst | 1 + > > > drivers/media/v4l2-core/v4l2-ioctl.c | 13 +++ > > > include/uapi/linux/videodev2.h | 23 +++++ > > > 4 files changed, 124 insertions(+) > > > create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-audio.rst > > > > > > diff --git a/Documentation/userspace-api/media/v4l/pixfmt-audio.rst b/Documentation/userspace-api/media/v4l/pixfmt-audio.rst > > > new file mode 100644 > > > index 000000000000..04b4a7fbd8f4 > > > --- /dev/null > > > +++ b/Documentation/userspace-api/media/v4l/pixfmt-audio.rst > > > @@ -0,0 +1,87 @@ > > > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later > > > + > > > +.. _pixfmt-audio: > > > + > > > +************* > > > +Audio Formats > > > +************* > > > + > > > +These formats are used for :ref:`audiomem2mem` interface only. > > > + > > > +.. tabularcolumns:: |p{5.8cm}|p{1.2cm}|p{10.3cm}| > > > + > > > +.. cssclass:: longtable > > > + > > > +.. flat-table:: Audio Format > > > + :header-rows: 1 > > > + :stub-columns: 0 > > > + :widths: 3 1 4 > > > + > > > + * - Identifier > > > + - Code > > > + - Details > > > + * .. _V4L2-AUDIO-FMT-S8: > > > + > > > + - ``V4L2_AUDIO_FMT_S8`` > > > + - 'S8' > > > + - Corresponds to SNDRV_PCM_FORMAT_S8 in ALSA > > > + * .. _V4L2-AUDIO-FMT-S16-LE: > > > > Hmm... why can't we just use SNDRV_*_FORMAT_*? Those are already part of > > an uAPI header. No need to add any abstraction here and/or redefine > > what is there already at include/uapi/sound/asound.h. > > > Actually I try to avoid including the include/uapi/sound/asound.h. > Because in user space, there is another copy in alsa-lib (asoundlib.h). > There will be conflict in userspace when including videodev2.h and > asoundlib.h. Well, alsasoundlib.h seems to be using the same definitions: https://github.com/michaelwu/alsa-lib/blob/master/include/pcm.h So, I can't see what would be the actual issue, as both userspace library and ALSA internal headers use the same magic numbers. You can still do things like: #ifdef __KERNEL__ # include <sound/asound.h> #else # include <asoundlib.h> #endif To avoid such kind of conflicts, if you need to have it included on some header file. Yet, I can't see why you would need that. IMO, at uAPI headers, you just need to declare the uAPI audiofmt field to be either __u32 or __u64, pointing it to where this value comes from (on both userspace and Kernelspace. E. g.: /** * struct v4l2_audio_format - audio data format definition * @audioformat: * an integer number matching the fields inside * enum snd_pcm_format_t (e. g. `SNDRV_PCM_FORMAT_*`), as defined * in include/uapi/sound/asound.h and * https://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html#gaa14b7f26877a812acbb39811364177f8. * @channels: channel numbers * @buffersize: maximum size in bytes required for data */ struct v4l2_audio_format { __u32 audioformat; __u32 channels; __u32 buffersize; } __attribute__ ((packed)); Then, at documentation you just need to point to where the possible values for SNDRV_PCM_FORMAT_ are defined. No need to document them one by one. With such definition, you'll only need to include sound/asound.h within the kAPI scope. > > And in the V4l framework, the fourcc type is commonly used in other > cases (video, radio, touch, meta....), to avoid changing common code > a lot, so I think using fourcc definition for audio may be simpler. Those are real video streams (or a video-related streams, in the case of metadata) where fourcc is widely used. There, it makes sense. However, ALSA format definitions are already being used for a long time. There's no sense on trying to reinvent it - or having an abstract layer to convert from/to fourcc <==> enum snd_pcm_format_t. Just use what is there already. Thanks, Mauro
On 22/02/2024 04:50, Shengjiu Wang wrote: > On Wed, Feb 21, 2024 at 7:10 PM Hans Verkuil <hverkuil@xs4all.nl> wrote: >> >> On 19/02/2024 13:56, Mauro Carvalho Chehab wrote: >>> Em Mon, 19 Feb 2024 12:05:02 +0800 >>> Shengjiu Wang <shengjiu.wang@gmail.com> escreveu: >>> >>>> Hi Mauro >>>> >>>> On Sat, Feb 17, 2024 at 5:19 PM Mauro Carvalho Chehab >>>> <mchehab@kernel.org> wrote: >>>>> >>>>> Em Thu, 18 Jan 2024 20:32:01 +0800 >>>>> Shengjiu Wang <shengjiu.wang@nxp.com> escreveu: >>>>> >>>>>> The audio sample format definition is from alsa, >>>>>> the header file is include/uapi/sound/asound.h, but >>>>>> don't include this header file directly, because in >>>>>> user space, there is another copy in alsa-lib. >>>>>> There will be conflict in userspace for include >>>>>> videodev2.h & asound.h and asoundlib.h >>>>>> >>>>>> Here still use the fourcc format. >>>>>> >>>>>> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com> >>>>>> --- >>>>>> .../userspace-api/media/v4l/pixfmt-audio.rst | 87 +++++++++++++++++++ >>>>>> .../userspace-api/media/v4l/pixfmt.rst | 1 + >>>>>> drivers/media/v4l2-core/v4l2-ioctl.c | 13 +++ >>>>>> include/uapi/linux/videodev2.h | 23 +++++ >>>>>> 4 files changed, 124 insertions(+) >>>>>> create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-audio.rst >>>>>> >>>>>> diff --git a/Documentation/userspace-api/media/v4l/pixfmt-audio.rst b/Documentation/userspace-api/media/v4l/pixfmt-audio.rst >>>>>> new file mode 100644 >>>>>> index 000000000000..04b4a7fbd8f4 >>>>>> --- /dev/null >>>>>> +++ b/Documentation/userspace-api/media/v4l/pixfmt-audio.rst >>>>>> @@ -0,0 +1,87 @@ >>>>>> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later >>>>>> + >>>>>> +.. _pixfmt-audio: >>>>>> + >>>>>> +************* >>>>>> +Audio Formats >>>>>> +************* >>>>>> + >>>>>> +These formats are used for :ref:`audiomem2mem` interface only. >>>>>> + >>>>>> +.. tabularcolumns:: |p{5.8cm}|p{1.2cm}|p{10.3cm}| >>>>>> + >>>>>> +.. cssclass:: longtable >>>>>> + >>>>>> +.. flat-table:: Audio Format >>>>>> + :header-rows: 1 >>>>>> + :stub-columns: 0 >>>>>> + :widths: 3 1 4 >>>>>> + >>>>>> + * - Identifier >>>>>> + - Code >>>>>> + - Details >>>>>> + * .. _V4L2-AUDIO-FMT-S8: >>>>>> + >>>>>> + - ``V4L2_AUDIO_FMT_S8`` >>>>>> + - 'S8' >>>>>> + - Corresponds to SNDRV_PCM_FORMAT_S8 in ALSA >>>>>> + * .. _V4L2-AUDIO-FMT-S16-LE: >>>>> >>>>> Hmm... why can't we just use SNDRV_*_FORMAT_*? Those are already part of >>>>> an uAPI header. No need to add any abstraction here and/or redefine >>>>> what is there already at include/uapi/sound/asound.h. >>>>> >>>> Actually I try to avoid including the include/uapi/sound/asound.h. >>>> Because in user space, there is another copy in alsa-lib (asoundlib.h). >>>> There will be conflict in userspace when including videodev2.h and >>>> asoundlib.h. >>> >>> Well, alsasoundlib.h seems to be using the same definitions: >>> https://github.com/michaelwu/alsa-lib/blob/master/include/pcm.h >>> >>> So, I can't see what would be the actual issue, as both userspace library >>> and ALSA internal headers use the same magic numbers. >>> >>> You can still do things like: >>> >>> #ifdef __KERNEL__ >>> # include <sound/asound.h> >>> #else >>> # include <asoundlib.h> >>> #endif >>> >>> To avoid such kind of conflicts, if you need to have it included on >>> some header file. Yet, I can't see why you would need that. >>> >>> IMO, at uAPI headers, you just need to declare the uAPI audiofmt field >>> to be either __u32 or __u64, pointing it to where this value comes from >>> (on both userspace and Kernelspace. E. g.: >>> >>> /** >>> * struct v4l2_audio_format - audio data format definition >>> * @audioformat: >>> * an integer number matching the fields inside >>> * enum snd_pcm_format_t (e. g. `SNDRV_PCM_FORMAT_*`), as defined >>> * in include/uapi/sound/asound.h and >>> * https://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html#gaa14b7f26877a812acbb39811364177f8. >>> * @channels: channel numbers >>> * @buffersize: maximum size in bytes required for data >>> */ >>> struct v4l2_audio_format { >>> __u32 audioformat; >>> __u32 channels; >>> __u32 buffersize; >>> } __attribute__ ((packed)); >>> >>> Then, at documentation you just need to point to where the >>> possible values for SNDRV_PCM_FORMAT_ are defined. No need to >>> document them one by one. >>> >>> With such definition, you'll only need to include sound/asound.h >>> within the kAPI scope. >>> >>>> >>>> And in the V4l framework, the fourcc type is commonly used in other >>>> cases (video, radio, touch, meta....), to avoid changing common code >>>> a lot, so I think using fourcc definition for audio may be simpler. >>> >>> Those are real video streams (or a video-related streams, in the case >>> of metadata) where fourcc is widely used. There, it makes sense. >>> However, ALSA format definitions are already being used for a long time. >>> There's no sense on trying to reinvent it - or having an abstract layer >>> to convert from/to fourcc <==> enum snd_pcm_format_t. Just use what is >>> there already. >> >> The problem is that within V4L2 we use fourcc consistently to describe a >> format, including in VIDIOC_ENUM_FMT. And the expectation is that the fourcc >> can be printed to a human readable string (there is even a printk format for >> that these days). >> >> But the pcm values are all small integers (and can even be 0!), and >> printing the fourcc will give garbage. It doesn't work well at all >> with the V4L2 API. But by having a straightforward conversion between the >> pcm identifier and a fourcc it was really easy to deal with this. >> >> There might even be applications today that call VIDIOC_ENUM_FMT to see >> what is supported and fail if it is not a proper fourcc is returned. >> >> It will certainly report nonsense in v4l_print_fmtdesc() (v4l2-ioctl.c). >> >> One of the early versions of this patch series did precisely what you request, >> but it just doesn't work well within the V4L2 uAPI. >> > > Thanks all. > > So can I reach the conclusion below? > 1. Keep using the fourcc definition for v4l2_audio_format.audioformat. > 2. Keep the name V4L2_BUF_TYPE_AUDIO_CAPTURE and > V4L2_BUF_TYPE_AUDIO_OUTPUT. > 3. Fix Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst > to change 'pixelformat' to 'audioformat'. > 4. Update Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst > to add more description for clock drift. Yes, let's go with that. Regards, Hans > > Best Regards > Shengjiu Wang > >> Regards, >> >> Hans >> >>> >>> Thanks, >>> Mauro >>
diff --git a/Documentation/userspace-api/media/v4l/pixfmt-audio.rst b/Documentation/userspace-api/media/v4l/pixfmt-audio.rst new file mode 100644 index 000000000000..04b4a7fbd8f4 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/pixfmt-audio.rst @@ -0,0 +1,87 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later + +.. _pixfmt-audio: + +************* +Audio Formats +************* + +These formats are used for :ref:`audiomem2mem` interface only. + +.. tabularcolumns:: |p{5.8cm}|p{1.2cm}|p{10.3cm}| + +.. cssclass:: longtable + +.. flat-table:: Audio Format + :header-rows: 1 + :stub-columns: 0 + :widths: 3 1 4 + + * - Identifier + - Code + - Details + * .. _V4L2-AUDIO-FMT-S8: + + - ``V4L2_AUDIO_FMT_S8`` + - 'S8' + - Corresponds to SNDRV_PCM_FORMAT_S8 in ALSA + * .. _V4L2-AUDIO-FMT-S16-LE: + + - ``V4L2_AUDIO_FMT_S16_LE`` + - 'S16_LE' + - Corresponds to SNDRV_PCM_FORMAT_S16_LE in ALSA + * .. _V4L2-AUDIO-FMT-U16-LE: + + - ``V4L2_AUDIO_FMT_U16_LE`` + - 'U16_LE' + - Corresponds to SNDRV_PCM_FORMAT_U16_LE in ALSA + * .. _V4L2-AUDIO-FMT-S24-LE: + + - ``V4L2_AUDIO_FMT_S24_LE`` + - 'S24_LE' + - Corresponds to SNDRV_PCM_FORMAT_S24_LE in ALSA + * .. _V4L2-AUDIO-FMT-U24-LE: + + - ``V4L2_AUDIO_FMT_U24_LE`` + - 'U24_LE' + - Corresponds to SNDRV_PCM_FORMAT_U24_LE in ALSA + * .. _V4L2-AUDIO-FMT-S32-LE: + + - ``V4L2_AUDIO_FMT_S32_LE`` + - 'S32_LE' + - Corresponds to SNDRV_PCM_FORMAT_S32_LE in ALSA + * .. _V4L2-AUDIO-FMT-U32-LE: + + - ``V4L2_AUDIO_FMT_U32_LE`` + - 'U32_LE' + - Corresponds to SNDRV_PCM_FORMAT_U32_LE in ALSA + * .. _V4L2-AUDIO-FMT-FLOAT-LE: + + - ``V4L2_AUDIO_FMT_FLOAT_LE`` + - 'FLOAT_LE' + - Corresponds to SNDRV_PCM_FORMAT_FLOAT_LE in ALSA + * .. _V4L2-AUDIO-FMT-IEC958-SUBFRAME-LE: + + - ``V4L2_AUDIO_FMT_IEC958_SUBFRAME_LE`` + - 'IEC958_SUBFRAME_LE' + - Corresponds to SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE in ALSA + * .. _V4L2-AUDIO-FMT-S24-3LE: + + - ``V4L2_AUDIO_FMT_S24_3LE`` + - 'S24_3LE' + - Corresponds to SNDRV_PCM_FORMAT_S24_3LE in ALSA + * .. _V4L2-AUDIO-FMT-U24-3LE: + + - ``V4L2_AUDIO_FMT_U24_3LE`` + - 'U24_3LE' + - Corresponds to SNDRV_PCM_FORMAT_U24_3LE in ALSA + * .. _V4L2-AUDIO-FMT-S20-3LE: + + - ``V4L2_AUDIO_FMT_S20_3LE`` + - 'S20_3LE' + - Corresponds to SNDRV_PCM_FORMAT_S24_3LE in ALSA + * .. _V4L2-AUDIO-FMT-U20-3LE: + + - ``V4L2_AUDIO_FMT_U20_3LE`` + - 'U20_3LE' + - Corresponds to SNDRV_PCM_FORMAT_U20_3LE in ALSA diff --git a/Documentation/userspace-api/media/v4l/pixfmt.rst b/Documentation/userspace-api/media/v4l/pixfmt.rst index 11dab4a90630..2eb6fdd3b43d 100644 --- a/Documentation/userspace-api/media/v4l/pixfmt.rst +++ b/Documentation/userspace-api/media/v4l/pixfmt.rst @@ -36,3 +36,4 @@ see also :ref:`VIDIOC_G_FBUF <VIDIOC_G_FBUF>`.) colorspaces colorspaces-defs colorspaces-details + pixfmt-audio diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index e7be7c2f302d..e5094f0e75c1 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -1471,6 +1471,19 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt) case V4L2_PIX_FMT_Y210: descr = "10-bit YUYV Packed"; break; case V4L2_PIX_FMT_Y212: descr = "12-bit YUYV Packed"; break; case V4L2_PIX_FMT_Y216: descr = "16-bit YUYV Packed"; break; + case V4L2_AUDIO_FMT_S8: descr = "8-bit Signed"; break; + case V4L2_AUDIO_FMT_S16_LE: descr = "16-bit Signed LE"; break; + case V4L2_AUDIO_FMT_U16_LE: descr = "16-bit Unsigned LE"; break; + case V4L2_AUDIO_FMT_S24_LE: descr = "24(32)-bit Signed LE"; break; + case V4L2_AUDIO_FMT_U24_LE: descr = "24(32)-bit Unsigned LE"; break; + case V4L2_AUDIO_FMT_S32_LE: descr = "32-bit Signed LE"; break; + case V4L2_AUDIO_FMT_U32_LE: descr = "32-bit Unsigned LE"; break; + case V4L2_AUDIO_FMT_FLOAT_LE: descr = "32-bit Float LE"; break; + case V4L2_AUDIO_FMT_IEC958_SUBFRAME_LE: descr = "32-bit IEC958 LE"; break; + case V4L2_AUDIO_FMT_S24_3LE: descr = "24(24)-bit Signed LE"; break; + case V4L2_AUDIO_FMT_U24_3LE: descr = "24(24)-bit Unsigned LE"; break; + case V4L2_AUDIO_FMT_S20_3LE: descr = "20(24)-bit Signed LE"; break; + case V4L2_AUDIO_FMT_U20_3LE: descr = "20(24)-bit Unsigned LE"; break; default: /* Compressed formats */ diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 57c82eb158f1..7d0b33e7d854 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -843,6 +843,29 @@ struct v4l2_pix_format { #define V4L2_META_FMT_RK_ISP1_PARAMS v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */ #define V4L2_META_FMT_RK_ISP1_STAT_3A v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */ +/* + * Audio-data formats + * All these audio formats use a fourcc starting with 'AU' + * followed by the SNDRV_PCM_FORMAT_ value from asound.h. + */ +#define V4L2_AUDIO_FMT_S8 v4l2_fourcc('A', 'U', '0', '0') +#define V4L2_AUDIO_FMT_S16_LE v4l2_fourcc('A', 'U', '0', '2') +#define V4L2_AUDIO_FMT_U16_LE v4l2_fourcc('A', 'U', '0', '4') +#define V4L2_AUDIO_FMT_S24_LE v4l2_fourcc('A', 'U', '0', '6') +#define V4L2_AUDIO_FMT_U24_LE v4l2_fourcc('A', 'U', '0', '8') +#define V4L2_AUDIO_FMT_S32_LE v4l2_fourcc('A', 'U', '1', '0') +#define V4L2_AUDIO_FMT_U32_LE v4l2_fourcc('A', 'U', '1', '2') +#define V4L2_AUDIO_FMT_FLOAT_LE v4l2_fourcc('A', 'U', '1', '4') +#define V4L2_AUDIO_FMT_IEC958_SUBFRAME_LE v4l2_fourcc('A', 'U', '1', '8') +#define V4L2_AUDIO_FMT_S24_3LE v4l2_fourcc('A', 'U', '3', '2') +#define V4L2_AUDIO_FMT_U24_3LE v4l2_fourcc('A', 'U', '3', '4') +#define V4L2_AUDIO_FMT_S20_3LE v4l2_fourcc('A', 'U', '3', '6') +#define V4L2_AUDIO_FMT_U20_3LE v4l2_fourcc('A', 'U', '3', '8') + +#define v4l2_fourcc_to_audfmt(fourcc) \ + (__force snd_pcm_format_t)(((((fourcc) >> 16) & 0xff) - '0') * 10 \ + + ((((fourcc) >> 24) & 0xff) - '0')) + /* priv field value to indicates that subsequent fields are valid. */ #define V4L2_PIX_FMT_PRIV_MAGIC 0xfeedcafe
The audio sample format definition is from alsa, the header file is include/uapi/sound/asound.h, but don't include this header file directly, because in user space, there is another copy in alsa-lib. There will be conflict in userspace for include videodev2.h & asound.h and asoundlib.h Here still use the fourcc format. Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com> --- .../userspace-api/media/v4l/pixfmt-audio.rst | 87 +++++++++++++++++++ .../userspace-api/media/v4l/pixfmt.rst | 1 + drivers/media/v4l2-core/v4l2-ioctl.c | 13 +++ include/uapi/linux/videodev2.h | 23 +++++ 4 files changed, 124 insertions(+) create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-audio.rst