Re: [PATCH v12 07/15] media: v4l2: Add audio capture and output support
From: Shengjiu Wang <shengjiu.wang@gmail.com>
Date: 2024-02-19 06:36:05
Also in:
alsa-devel, linux-media, lkml
Hi Mauro, Hans On Sat, Feb 17, 2024 at 5:42 PM Mauro Carvalho Chehab [off-list ref] wrote:
Em Thu, 18 Jan 2024 20:32:00 +0800 Shengjiu Wang [off-list ref] escreveu:quoted
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/v4l-audioX". Signed-off-by: Shengjiu Wang <redacted> --- .../userspace-api/media/v4l/buffer.rst | 6 ++ .../media/v4l/dev-audio-mem2mem.rst | 71 +++++++++++++++++++ .../userspace-api/media/v4l/devices.rst | 1 + .../media/v4l/vidioc-enum-fmt.rst | 2 + .../userspace-api/media/v4l/vidioc-g-fmt.rst | 4 ++ .../media/videodev2.h.rst.exceptions | 2 + .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++ drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++ drivers/media/v4l2-core/v4l2-dev.c | 17 +++++ drivers/media/v4l2-core/v4l2-ioctl.c | 53 ++++++++++++++ include/media/v4l2-dev.h | 2 + include/media/v4l2-ioctl.h | 34 +++++++++ include/uapi/linux/videodev2.h | 17 +++++ 13 files changed, 222 insertions(+) create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rstdiff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst index 52bbee81c080..a3754ca6f0d6 100644 --- a/Documentation/userspace-api/media/v4l/buffer.rst +++ b/Documentation/userspace-api/media/v4l/buffer.rst@@ -438,6 +438,12 @@ enum v4l2_buf_type * - ``V4L2_BUF_TYPE_META_OUTPUT`` - 14quoted
- Buffer for metadata output, see :ref:`metadata`. + * - ``V4L2_BUF_TYPE_AUDIO_CAPTURE`` + - 15 + - Buffer for audio capture, see :ref:`audio`. + * - ``V4L2_BUF_TYPE_AUDIO_OUTPUT`` + - 16Hmm... alsa APi define input/output as: enum { SNDRV_PCM_STREAM_PLAYBACK = 0, SNDRV_PCM_STREAM_CAPTURE, SNDRV_PCM_STREAM_LAST = SNDRV_PCM_STREAM_CAPTURE, }; I would use a namespace as close as possible to the ALSA API. Also, we're not talking about V4L2, but, instead audio. so, not sure if I like the prefix to start with V4L2_. Maybe ALSA_? So, a better namespace would be: ${prefix}_BUF_TYPE_PCM_STREAM_PLAYBACK and ${prefix}_BUF_TYPE_PCM_STREAM_CAPTURE
Ok, So can I use the name below? V4L2_BUF_TYPE_PCM_STREAM_PLAYBACK V4L2_BUF_TYPE_PCM_STREAM_CAPTURE
quoted
+ - Buffer for audio output, see :ref:`audio`. .. _buffer-flags:diff --git a/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst new file mode 100644 index 000000000000..68faecfe3a02 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst@@ -0,0 +1,71 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later + +.. _audiomem2mem: + +******************************** +Audio Memory-To-Memory Interface +******************************** + +An audio memory-to-memory device can compress, decompress, transform, or +otherwise convert audio data from one format into another format, in memory. +Such memory-to-memory devices set the ``V4L2_CAP_AUDIO_M2M`` capability. +Examples of memory-to-memory devices are audio codecs, audio preprocessing, +audio postprocessing. + +A memory-to-memory audio node supports both output (sending audio frames from +memory to the hardware) and capture (receiving the processed audio frames +from the hardware into memory) stream I/O. An application will have to +setup the stream I/O for both sides and finally call +:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` for both capture and output to +start the hardware. + +Memory-to-memory devices function as a shared resource: you can +open the audio node multiple times, each application setting up their +own properties that are local to the file handle, and each can use +it independently from the others. The driver will arbitrate access to +the hardware and reprogram it whenever another file handler gets access. + +Audio memory-to-memory devices are accessed through character device +special files named ``/dev/v4l-audio`` + +Querying Capabilities +===================== + +Device nodes supporting the audio memory-to-memory interface set the +``V4L2_CAP_AUDIO_M2M`` flag in the ``device_caps`` field of the +:c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP` +ioctl. + +Data Format Negotiation +======================= + +The audio device uses the :ref:`format` ioctls to select the capture format. +The audio buffer content format is bound to that selected format. In addition +to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be +supported as well. + +To use the :ref:`format` ioctls applications set the ``type`` field of the +:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_AUDIO_CAPTURE`` or to +``V4L2_BUF_TYPE_AUDIO_OUTPUT``. Both drivers and applications must set the +remainder of the :c:type:`v4l2_format` structure to 0. + +.. c:type:: v4l2_audio_format + +.. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}| + +.. flat-table:: struct v4l2_audio_format + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``pixelformat`` + - The sample format, set by the application. see :ref:`pixfmt-audio`pixelformat doesn't make any sense for audio: there are no pixels on a PCM stream. Please use call it, instead: `snd_pcm_format`, making it match the values for snd_pcm_format_t. Yet, I would keep defining it as u32 (or u64?) instead of using a typedef int field there (snd_pcm_format_t), as the size of integer is different on 32 and 64 bit kernels.quoted
+ * - __u32 + - ``channels`` + - The channel number, set by the application. channel number range is + [1, 32].Why not start on zero?
channels in audio are at least 1.
quoted
+ * - __u32 + - ``buffersize`` + - Maximum buffer size in bytes required for data. The value is set by the + driver.diff --git a/Documentation/userspace-api/media/v4l/devices.rst b/Documentation/userspace-api/media/v4l/devices.rst index 8bfbad65a9d4..758bd90f1c26 100644 --- a/Documentation/userspace-api/media/v4l/devices.rst +++ b/Documentation/userspace-api/media/v4l/devices.rst@@ -24,3 +24,4 @@ Interfaces dev-event dev-subdev dev-meta + dev-audio-mem2memdiff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst index 000c154b0f98..42deb07f4ff4 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst@@ -96,6 +96,8 @@ the ``mbus_code`` field is handled differently: ``V4L2_BUF_TYPE_VIDEO_OVERLAY``, ``V4L2_BUF_TYPE_SDR_CAPTURE``, ``V4L2_BUF_TYPE_SDR_OUTPUT``, + ``V4L2_BUF_TYPE_AUDIO_CAPTURE``, + ``V4L2_BUF_TYPE_AUDIO_OUTPUT``, ``V4L2_BUF_TYPE_META_CAPTURE`` and ``V4L2_BUF_TYPE_META_OUTPUT``. See :c:type:`v4l2_buf_type`.diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst index 675c385e5aca..528fd9df41aa 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst@@ -130,6 +130,10 @@ The format as returned by :ref:`VIDIOC_TRY_FMT <VIDIOC_G_FMT>` must be identical - ``meta`` - Definition of a metadata format, see :ref:`meta-formats`, used by metadata capture devices. + * - struct :c:type:`v4l2_audio_format` + - ``audio`` + - Definition of a audio data format, see :ref:`audiomem2mem`, used by + audio memory-to-memory devices * - __u8 - ``raw_data``\ [200] - Place holder for future extensions.diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions index da6d0b8e4c2c..e61152bb80d1 100644 --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions@@ -29,6 +29,8 @@ replace symbol V4L2_FIELD_SEQ_TB :c:type:`v4l2_field` replace symbol V4L2_FIELD_TOP :c:type:`v4l2_field` # Documented enum v4l2_buf_type +replace symbol V4L2_BUF_TYPE_AUDIO_CAPTURE :c:type:`v4l2_buf_type` +replace symbol V4L2_BUF_TYPE_AUDIO_OUTPUT :c:type:`v4l2_buf_type` replace symbol V4L2_BUF_TYPE_META_CAPTURE :c:type:`v4l2_buf_type` replace symbol V4L2_BUF_TYPE_META_OUTPUT :c:type:`v4l2_buf_type` replace symbol V4L2_BUF_TYPE_SDR_CAPTURE :c:type:`v4l2_buf_type`diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index 54d572c3b515..16ab204d15b0 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c@@ -791,6 +791,10 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) case V4L2_BUF_TYPE_META_OUTPUT: requested_sizes[0] = f->fmt.meta.buffersize; break; + case V4L2_BUF_TYPE_AUDIO_CAPTURE: + case V4L2_BUF_TYPE_AUDIO_OUTPUT: + requested_sizes[0] = f->fmt.audio.buffersize; + break; default: return -EINVAL; }diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 8c07400bd280..5e94db8dfdae 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c@@ -101,6 +101,7 @@ struct v4l2_format32 { struct v4l2_sliced_vbi_format sliced; struct v4l2_sdr_format sdr; struct v4l2_meta_format meta; + struct v4l2_audio_format audio; __u8 raw_data[200]; /* user-defined */ } fmt; };@@ -166,6 +167,10 @@ static int get_v4l2_format32(struct v4l2_format *p64, case V4L2_BUF_TYPE_META_OUTPUT: return copy_from_user(&p64->fmt.meta, &p32->fmt.meta, sizeof(p64->fmt.meta)) ? -EFAULT : 0; + case V4L2_BUF_TYPE_AUDIO_CAPTURE: + case V4L2_BUF_TYPE_AUDIO_OUTPUT: + return copy_from_user(&p64->fmt.audio, &p32->fmt.audio, + sizeof(p64->fmt.audio)) ? -EFAULT : 0; default: return -EINVAL; }@@ -216,6 +221,10 @@ static int put_v4l2_format32(struct v4l2_format *p64, case V4L2_BUF_TYPE_META_OUTPUT: return copy_to_user(&p32->fmt.meta, &p64->fmt.meta, sizeof(p64->fmt.meta)) ? -EFAULT : 0; + case V4L2_BUF_TYPE_AUDIO_CAPTURE: + case V4L2_BUF_TYPE_AUDIO_OUTPUT: + return copy_to_user(&p32->fmt.audio, &p64->fmt.audio, + sizeof(p64->fmt.audio)) ? -EFAULT : 0; default: return -EINVAL; }diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c index d13954bd31fd..bac008fcedc6 100644 --- a/drivers/media/v4l2-core/v4l2-dev.c +++ b/drivers/media/v4l2-core/v4l2-dev.c@@ -553,6 +553,7 @@ static void determine_valid_ioctls(struct video_device *vdev) bool is_tch = vdev->vfl_type == VFL_TYPE_TOUCH; bool is_meta = vdev->vfl_type == VFL_TYPE_VIDEO && (vdev->device_caps & meta_caps); + bool is_audio = vdev->vfl_type == VFL_TYPE_AUDIO; bool is_rx = vdev->vfl_dir != VFL_DIR_TX; bool is_tx = vdev->vfl_dir != VFL_DIR_RX; bool is_io_mc = vdev->device_caps & V4L2_CAP_IO_MC;@@ -666,6 +667,19 @@ static void determine_valid_ioctls(struct video_device *vdev) SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_meta_out); SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_meta_out); } + if (is_audio && is_rx) { + /* audio capture specific ioctls */ + SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_cap); + SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_cap); + SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_cap); + SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_cap); + } else if (is_audio && is_tx) { + /* audio output specific ioctls */ + SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_out); + SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_out); + SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_out); + SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_out); + } if (is_vbi) { /* vbi specific ioctls */ if ((is_rx && (ops->vidioc_g_fmt_vbi_cap ||@@ -929,6 +943,9 @@ int __video_register_device(struct video_device *vdev, case VFL_TYPE_TOUCH: name_base = "v4l-touch"; break; + case VFL_TYPE_AUDIO: + name_base = "v4l-audio"; + break; default: pr_err("%s called with unknown type: %d\n", __func__, type);diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 33076af4dfdb..e7be7c2f302d 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c@@ -188,6 +188,8 @@ const char *v4l2_type_names[] = { [V4L2_BUF_TYPE_SDR_OUTPUT] = "sdr-out", [V4L2_BUF_TYPE_META_CAPTURE] = "meta-cap", [V4L2_BUF_TYPE_META_OUTPUT] = "meta-out", + [V4L2_BUF_TYPE_AUDIO_CAPTURE] = "audio-cap", + [V4L2_BUF_TYPE_AUDIO_OUTPUT] = "audio-out", }; EXPORT_SYMBOL(v4l2_type_names);@@ -276,6 +278,7 @@ static void v4l_print_format(const void *arg, bool write_only) const struct v4l2_sliced_vbi_format *sliced; const struct v4l2_window *win; const struct v4l2_meta_format *meta; + const struct v4l2_audio_format *audio; u32 pixelformat; u32 planes; unsigned i;@@ -346,6 +349,13 @@ static void v4l_print_format(const void *arg, bool write_only) pr_cont(", dataformat=%p4cc, buffersize=%u\n", &pixelformat, meta->buffersize); break; + case V4L2_BUF_TYPE_AUDIO_CAPTURE: + case V4L2_BUF_TYPE_AUDIO_OUTPUT: + audio = &p->fmt.audio; + pixelformat = audio->audioformat; + pr_cont(", format=%p4cc, channels=%u, buffersize=%u\n", + &pixelformat, audio->channels, audio->buffersize); + break; } }@@ -927,6 +937,7 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type) bool is_tch = vfd->vfl_type == VFL_TYPE_TOUCH; bool is_meta = vfd->vfl_type == VFL_TYPE_VIDEO && (vfd->device_caps & meta_caps); + bool is_audio = vfd->vfl_type == VFL_TYPE_AUDIO; bool is_rx = vfd->vfl_dir != VFL_DIR_TX; bool is_tx = vfd->vfl_dir != VFL_DIR_RX;@@ -992,6 +1003,14 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type) if (is_meta && is_tx && ops->vidioc_g_fmt_meta_out) return 0; break; + case V4L2_BUF_TYPE_AUDIO_CAPTURE: + if (is_audio && is_rx && ops->vidioc_g_fmt_audio_cap) + return 0; + break; + case V4L2_BUF_TYPE_AUDIO_OUTPUT: + if (is_audio && is_tx && ops->vidioc_g_fmt_audio_out) + return 0; + break; default: break; }@@ -1597,6 +1616,16 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops, break; ret = ops->vidioc_enum_fmt_meta_out(file, fh, arg); break; + case V4L2_BUF_TYPE_AUDIO_CAPTURE: + if (unlikely(!ops->vidioc_enum_fmt_audio_cap)) + break; + ret = ops->vidioc_enum_fmt_audio_cap(file, fh, arg); + break; + case V4L2_BUF_TYPE_AUDIO_OUTPUT: + if (unlikely(!ops->vidioc_enum_fmt_audio_out)) + break; + ret = ops->vidioc_enum_fmt_audio_out(file, fh, arg); + break; } if (ret == 0) v4l_fill_fmtdesc(p);@@ -1673,6 +1702,10 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops, return ops->vidioc_g_fmt_meta_cap(file, fh, arg); case V4L2_BUF_TYPE_META_OUTPUT: return ops->vidioc_g_fmt_meta_out(file, fh, arg); + case V4L2_BUF_TYPE_AUDIO_CAPTURE: + return ops->vidioc_g_fmt_audio_cap(file, fh, arg); + case V4L2_BUF_TYPE_AUDIO_OUTPUT: + return ops->vidioc_g_fmt_audio_out(file, fh, arg); } return -EINVAL; }@@ -1784,6 +1817,16 @@ static int v4l_s_fmt(const struct v4l2_ioctl_ops *ops, break; memset_after(p, 0, fmt.meta); return ops->vidioc_s_fmt_meta_out(file, fh, arg); + case V4L2_BUF_TYPE_AUDIO_CAPTURE: + if (unlikely(!ops->vidioc_s_fmt_audio_cap)) + break; + memset_after(p, 0, fmt.audio); + return ops->vidioc_s_fmt_audio_cap(file, fh, arg); + case V4L2_BUF_TYPE_AUDIO_OUTPUT: + if (unlikely(!ops->vidioc_s_fmt_audio_out)) + break; + memset_after(p, 0, fmt.audio); + return ops->vidioc_s_fmt_audio_out(file, fh, arg); } return -EINVAL; }@@ -1892,6 +1935,16 @@ static int v4l_try_fmt(const struct v4l2_ioctl_ops *ops, break; memset_after(p, 0, fmt.meta); return ops->vidioc_try_fmt_meta_out(file, fh, arg); + case V4L2_BUF_TYPE_AUDIO_CAPTURE: + if (unlikely(!ops->vidioc_try_fmt_audio_cap)) + break; + memset_after(p, 0, fmt.audio); + return ops->vidioc_try_fmt_audio_cap(file, fh, arg); + case V4L2_BUF_TYPE_AUDIO_OUTPUT: + if (unlikely(!ops->vidioc_try_fmt_audio_out)) + break; + memset_after(p, 0, fmt.audio); + return ops->vidioc_try_fmt_audio_out(file, fh, arg); } return -EINVAL; }diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h index d82dfdbf6e58..82b63f82d43f 100644 --- a/include/media/v4l2-dev.h +++ b/include/media/v4l2-dev.h@@ -30,6 +30,7 @@ * @VFL_TYPE_SUBDEV: for V4L2 subdevices * @VFL_TYPE_SDR: for Software Defined Radio tuners * @VFL_TYPE_TOUCH: for touch sensors + * @VFL_TYPE_AUDIO: for audio memory-to-memory devices * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum */ enum vfl_devnode_type {@@ -39,6 +40,7 @@ enum vfl_devnode_type { VFL_TYPE_SUBDEV, VFL_TYPE_SDR, VFL_TYPE_TOUCH, + VFL_TYPE_AUDIO, VFL_TYPE_MAX /* Shall be the last one */ };diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h index edb733f21604..f840cf740ce1 100644 --- a/include/media/v4l2-ioctl.h +++ b/include/media/v4l2-ioctl.h@@ -45,6 +45,12 @@ struct v4l2_fh; * @vidioc_enum_fmt_meta_out: pointer to the function that implements * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic * for metadata output + * @vidioc_enum_fmt_audio_cap: pointer to the function that implements + * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic + * for audio capture + * @vidioc_enum_fmt_audio_out: pointer to the function that implements + * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic + * for audio output * @vidioc_g_fmt_vid_cap: pointer to the function that implements * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for video capture * in single plane mode@@ -79,6 +85,10 @@ struct v4l2_fh; * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata capture * @vidioc_g_fmt_meta_out: pointer to the function that implements * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata output + * @vidioc_g_fmt_audio_cap: pointer to the function that implements + * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio capture + * @vidioc_g_fmt_audio_out: pointer to the function that implements + * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio output * @vidioc_s_fmt_vid_cap: pointer to the function that implements * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for video capture * in single plane mode@@ -113,6 +123,10 @@ struct v4l2_fh; * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata capture * @vidioc_s_fmt_meta_out: pointer to the function that implements * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata output + * @vidioc_s_fmt_audio_cap: pointer to the function that implements + * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio capture + * @vidioc_s_fmt_audio_out: pointer to the function that implements + * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio output * @vidioc_try_fmt_vid_cap: pointer to the function that implements * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for video capture * in single plane mode@@ -149,6 +163,10 @@ struct v4l2_fh; * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata capture * @vidioc_try_fmt_meta_out: pointer to the function that implements * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata output + * @vidioc_try_fmt_audio_cap: pointer to the function that implements + * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio capture + * @vidioc_try_fmt_audio_out: pointer to the function that implements + * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio output * @vidioc_reqbufs: pointer to the function that implements * :ref:`VIDIOC_REQBUFS <vidioc_reqbufs>` ioctl * @vidioc_querybuf: pointer to the function that implements@@ -315,6 +333,10 @@ struct v4l2_ioctl_ops { struct v4l2_fmtdesc *f); int (*vidioc_enum_fmt_meta_out)(struct file *file, void *fh, struct v4l2_fmtdesc *f); + int (*vidioc_enum_fmt_audio_cap)(struct file *file, void *fh, + struct v4l2_fmtdesc *f); + int (*vidioc_enum_fmt_audio_out)(struct file *file, void *fh, + struct v4l2_fmtdesc *f); /* VIDIOC_G_FMT handlers */ int (*vidioc_g_fmt_vid_cap)(struct file *file, void *fh,@@ -345,6 +367,10 @@ struct v4l2_ioctl_ops { struct v4l2_format *f); int (*vidioc_g_fmt_meta_out)(struct file *file, void *fh, struct v4l2_format *f); + int (*vidioc_g_fmt_audio_cap)(struct file *file, void *fh, + struct v4l2_format *f); + int (*vidioc_g_fmt_audio_out)(struct file *file, void *fh, + struct v4l2_format *f); /* VIDIOC_S_FMT handlers */ int (*vidioc_s_fmt_vid_cap)(struct file *file, void *fh,@@ -375,6 +401,10 @@ struct v4l2_ioctl_ops { struct v4l2_format *f); int (*vidioc_s_fmt_meta_out)(struct file *file, void *fh, struct v4l2_format *f); + int (*vidioc_s_fmt_audio_cap)(struct file *file, void *fh, + struct v4l2_format *f); + int (*vidioc_s_fmt_audio_out)(struct file *file, void *fh, + struct v4l2_format *f); /* VIDIOC_TRY_FMT handlers */ int (*vidioc_try_fmt_vid_cap)(struct file *file, void *fh,@@ -405,6 +435,10 @@ struct v4l2_ioctl_ops { struct v4l2_format *f); int (*vidioc_try_fmt_meta_out)(struct file *file, void *fh, struct v4l2_format *f); + int (*vidioc_try_fmt_audio_cap)(struct file *file, void *fh, + struct v4l2_format *f); + int (*vidioc_try_fmt_audio_out)(struct file *file, void *fh, + struct v4l2_format *f); /* Buffer handlers */ int (*vidioc_reqbufs)(struct file *file, void *fh,diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 6cd65969c2b5..57c82eb158f1 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h@@ -153,6 +153,8 @@ enum v4l2_buf_type { V4L2_BUF_TYPE_SDR_OUTPUT = 12, V4L2_BUF_TYPE_META_CAPTURE = 13, V4L2_BUF_TYPE_META_OUTPUT = 14, + V4L2_BUF_TYPE_AUDIO_CAPTURE = 15, + V4L2_BUF_TYPE_AUDIO_OUTPUT = 16, /* Deprecated, do not use */ V4L2_BUF_TYPE_PRIVATE = 0x80, };@@ -169,6 +171,7 @@ enum v4l2_buf_type { || (type) == V4L2_BUF_TYPE_VBI_OUTPUT \ || (type) == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT \ || (type) == V4L2_BUF_TYPE_SDR_OUTPUT \ + || (type) == V4L2_BUF_TYPE_AUDIO_OUTPUT \ || (type) == V4L2_BUF_TYPE_META_OUTPUT) #define V4L2_TYPE_IS_CAPTURE(type) (!V4L2_TYPE_IS_OUTPUT(type))@@ -2423,6 +2426,18 @@ struct v4l2_meta_format { __u32 buffersize; } __attribute__ ((packed)); +/** + * struct v4l2_audio_format - audio data format definition + * @audioformat: little endian four character code (fourcc)Don't use fourcc here. Instead, use the types defined at snd_pcm_format_t.
In the earlier version of this patch series, fourcc is not used in this
struct v4l2_audio_format.
I use "__u32 audioformat", the value is from snd_pcm_format_t.
Using "__u32" is in order to avoid including the include/uapi/sound/asound.h
header.
And defined V4L2_AUDIO_FMT_LPCM for the v4l2_fmtdesc.pixelformat
#define V4L2_AUDIO_FMT_LPCM v4l2_fourcc('L', 'P', 'C', 'M') /*
audio lpcm */
After discussing with Hans, I use the current way for v4l audio.
Hans:
Not sure if you can accept going back to the previous solution?
You have already done similar changes in v4l-utils.
Best regards
Shengjiu Wangquoted
+ * @channels: channel numbers + * @buffersize: maximum size in bytes required for data + */ +struct v4l2_audio_format { + __u32 audioformat; + __u32 channels; + __u32 buffersize; +} __attribute__ ((packed)); + /** * struct v4l2_format - stream data format * @type: enum v4l2_buf_type; type of the data stream@@ -2431,6 +2446,7 @@ struct v4l2_meta_format { * @win: definition of an overlaid image * @vbi: raw VBI capture or output parameters * @sliced: sliced VBI capture or output parameters + * @audio: definition of an audio format * @raw_data: placeholder for future extensions and custom formats * @fmt: union of @pix, @pix_mp, @win, @vbi, @sliced, @sdr, @meta * and @raw_data@@ -2445,6 +2461,7 @@ struct v4l2_format { struct v4l2_sliced_vbi_format sliced; /* V4L2_BUF_TYPE_SLICED_VBI_CAPTURE */ struct v4l2_sdr_format sdr; /* V4L2_BUF_TYPE_SDR_CAPTURE */ struct v4l2_meta_format meta; /* V4L2_BUF_TYPE_META_CAPTURE */ + struct v4l2_audio_format audio; /* V4L2_BUF_TYPE_AUDIO_CAPTURE */ __u8 raw_data[200]; /* user-defined */ } fmt; };Thanks, Mauro