[PATCH v15 09/16] media: uapi: Define audio sample format fourcc type

Shengjiu Wang shengjiu.wang at nxp.com
Tue Mar 19 18:51:07 AEDT 2024


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 at nxp.com>
---
 .../userspace-api/media/v4l/pixfmt-audio.rst  | 100 ++++++++++++++++++
 .../userspace-api/media/v4l/pixfmt.rst        |   1 +
 drivers/media/v4l2-core/v4l2-ioctl.c          |  13 +++
 include/uapi/linux/videodev2.h                |  29 +++++
 4 files changed, 143 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..a66db9a19936
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/pixfmt-audio.rst
@@ -0,0 +1,100 @@
+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+
+.. _pixfmt-audio:
+
+*************
+Audio Formats
+*************
+
+These formats are used for :ref:`audiomem2mem` interface only.
+
+All FourCCs starting with 'AU' are reserved for mappings
+of the snd_pcm_format_t type.
+
+The v4l2_audfmt_to_fourcc() is defined to convert the snd_pcm_format_t
+type to a FourCC. The first character is 'A', the second character
+is 'U', and the remaining two characters is the snd_pcm_format_t
+value in ASCII. Example: SNDRV_PCM_FORMAT_S16_LE (with value 2)
+maps to 'AU02' and SNDRV_PCM_FORMAT_S24_3LE (with value 32) maps
+to 'AU32'."
+
+The v4l2_fourcc_to_audfmt() is defined to convert these FourCCs to
+snd_pcm_format_t type.
+
+.. 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 961abcdf7290..be229c69e991 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 2c03d2dfadbe..c7b1bfad82c4 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -843,6 +843,35 @@ 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.
+ *
+ * FourCCs starting with 'AU' are reserved for the snd_pcm_format_t
+ * to fourcc mappings
+ */
+#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'))
+
+#define v4l2_audfmt_to_fourcc(audfmt) \
+	v4l2_fourcc('A', 'U', '0' + (__force int)(audfmt) / 10, '0' + (__force int)(audfmt) % 10)
+
 /* priv field value to indicates that subsequent fields are valid. */
 #define V4L2_PIX_FMT_PRIV_MAGIC		0xfeedcafe
 
-- 
2.34.1



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