lineage-rockchip/android_external_ffmpeg
1
0
Fork 0
Code Activity Actions

avcodec/v4l2request: Probe for a capable media and video device

Browse source 
Probe all media devices and its linked video devices to locate a video
device that support stateless decoding of the specific codec using the
V4L2 Request API.

When AVV4L2RequestDeviceContext.media_fd is a valid file descriptor only
video devices for the opened media device is probed.
E.g. using a -init_hw_device v4l2request:/dev/media1 parameter.

A video device is deemed capable when all tests pass, e.g. kernel driver
support the codec, FFmpeg v4l2-request code know about the buffer format
and kernel driver report that the frame size is supported.

A codec specific hook, post_probe, is supported to e.g. test for codec
specific limitations, PROFILE and LEVEL controls.

Basic flow for initialization follow the kernel Memory-to-memory
Stateless Video Decoder Interface > Initialization [1].

[1] https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/dev-stateless-decoder.html#initialization

Co-developed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Co-developed-by: Alex Bee <knaerzche@gmail.com>
Signed-off-by: Alex Bee <knaerzche@gmail.com>
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
This commit is contained in:
Jonas Karlman 2024-08-06 09:06:02 +00:00 • committed by Your Name
parent 2c23dd4ddb
commit 90124e1139
5 changed files with 641 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

4
configure vendored
View file

@ -1966,6 +1966,7 @@ EXTERNAL_LIBRARY_LIST="
libtorch
libtwolame
libuavs3d
libudev
libv4l2
libvmaf
libvorbis
@ -3148,7 +3149,7 @@ dxva2_deps="dxva2api_h DXVA2_ConfigPictureDecode ole32 user32"
ffnvcodec_deps_any="libdl LoadLibrary"
mediacodec_deps="android mediandk"
nvdec_deps="ffnvcodec"
v4l2_request_deps="linux_media_h v4l2_timeval_to_ns"
v4l2_request_deps="linux_media_h v4l2_timeval_to_ns libdrm libudev"
vaapi_x11_deps="xlib_x11"
videotoolbox_hwaccel_deps="videotoolbox pthreads"
videotoolbox_hwaccel_extralibs="-framework QuartzCore"
@ -7202,6 +7203,7 @@ fi
if enabled v4l2_request; then
check_func_headers "linux/media.h linux/videodev2.h" v4l2_timeval_to_ns
check_pkg_config libudev libudev libudev.h udev_new
fi
check_headers sys/videoio.h

2
libavcodec/Makefile
View file

@ -176,7 +176,7 @@ OBJS-$(CONFIG_VP3DSP) += vp3dsp.o
OBJS-$(CONFIG_VP56DSP) += vp56dsp.o
OBJS-$(CONFIG_VP8DSP) += vp8dsp.o
OBJS-$(CONFIG_V4L2_M2M) += v4l2_m2m.o v4l2_context.o v4l2_buffers.o v4l2_fmt.o
OBJS-$(CONFIG_V4L2_REQUEST) += v4l2_request.o
OBJS-$(CONFIG_V4L2_REQUEST) += v4l2_request.o v4l2_request_probe.o
OBJS-$(CONFIG_WMA_FREQS) += wma_freqs.o
OBJS-$(CONFIG_WMV2DSP) += wmv2dsp.o

18
libavcodec/v4l2_request.c
View file

@ -244,7 +244,11 @@ static AVBufferRef *v4l2_request_frame_alloc(void *opaque, size_t size)
return NULL;
}
// TODO: Set AVDRMFrameDescriptor of this AVFrame
// Set AVDRMFrameDescriptor of this AVFrame
if (ff_v4l2_request_set_drm_descriptor(desc, &ctx->format) < 0) {
av_buffer_unref(&ref);
return NULL;
}
return ref;
}
@ -261,8 +265,7 @@ int ff_v4l2_request_frame_params(AVCodecContext *avctx,
AVHWFramesContext *hwfc = (AVHWFramesContext *)hw_frames_ctx->data;
hwfc->format = AV_PIX_FMT_DRM_PRIME;
// TODO: Set sw_format based on capture buffer format
hwfc->sw_format = AV_PIX_FMT_NONE;
hwfc->sw_format = ff_v4l2_request_get_sw_format(&ctx->format);
if (V4L2_TYPE_IS_MULTIPLANAR(ctx->format.type)) {
hwfc->width = ctx->format.fmt.pix_mp.width;
@ -413,6 +416,7 @@ int ff_v4l2_request_init(AVCodecContext *avctx,
{
V4L2RequestContext *ctx = v4l2_request_context(avctx);
AVV4L2RequestDeviceContext *hwctx = NULL;
int ret;
// Set initial default values
ctx->av_class = &v4l2_request_context_class;
@ -428,7 +432,13 @@ int ff_v4l2_request_init(AVCodecContext *avctx,
}
}
// TODO: Probe for a capable media and video device
// Probe for a capable media and video device for the V4L2 codec pixelformat
ret = ff_v4l2_request_probe(avctx, pixelformat, buffersize, control, count);
if (ret < 0) {
av_log(avctx, AV_LOG_INFO, "No V4L2 video device found for %s\n",
av_fourcc2str(pixelformat));
return ret;
}
// Transfer (or return) ownership of media device file descriptor to hwdevice
if (hwctx) {

9
libavcodec/v4l2_request_internal.h
View file

@ -39,4 +39,13 @@ static inline V4L2RequestFrameDescriptor *v4l2_request_framedesc(AVFrame *frame)
return (V4L2RequestFrameDescriptor *)frame->data[0];
}
enum AVPixelFormat ff_v4l2_request_get_sw_format(struct v4l2_format *format);
int ff_v4l2_request_set_drm_descriptor(V4L2RequestFrameDescriptor *framedesc,
struct v4l2_format *format);
int ff_v4l2_request_probe(AVCodecContext *avctx, uint32_t pixelformat,
uint32_t buffersize, struct v4l2_ext_control *control,
int count);
#endif /* AVCODEC_V4L2_REQUEST_INTERNAL_H */

614
libavcodec/v4l2_request_probe.c Normal file
View file

@ -0,0 +1,614 @@
/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "config.h"
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <unistd.h>
#include <drm_fourcc.h>
#include <libudev.h>
#include "libavutil/hwcontext_v4l2request.h"
#include "libavutil/mem.h"
#include "v4l2_request_internal.h"
static const struct {
uint32_t pixelformat;
enum AVPixelFormat sw_format;
uint32_t drm_format;
uint64_t format_modifier;
} v4l2_request_capture_pixelformats[] = {
{ V4L2_PIX_FMT_NV12, AV_PIX_FMT_NV12, DRM_FORMAT_NV12, DRM_FORMAT_MOD_LINEAR },
#if defined(V4L2_PIX_FMT_NV12_32L32)
{ V4L2_PIX_FMT_NV12_32L32, AV_PIX_FMT_NONE, DRM_FORMAT_NV12, DRM_FORMAT_MOD_ALLWINNER_TILED },
#endif
#if defined(V4L2_PIX_FMT_NV15) && defined(DRM_FORMAT_NV15)
{ V4L2_PIX_FMT_NV15, AV_PIX_FMT_NONE, DRM_FORMAT_NV15, DRM_FORMAT_MOD_LINEAR },
#endif
{ V4L2_PIX_FMT_NV16, AV_PIX_FMT_NV16, DRM_FORMAT_NV16, DRM_FORMAT_MOD_LINEAR },
#if defined(V4L2_PIX_FMT_NV20) && defined(DRM_FORMAT_NV20)
{ V4L2_PIX_FMT_NV20, AV_PIX_FMT_NONE, DRM_FORMAT_NV20, DRM_FORMAT_MOD_LINEAR },
#endif
#if defined(V4L2_PIX_FMT_P010) && defined(DRM_FORMAT_P010)
{ V4L2_PIX_FMT_P010, AV_PIX_FMT_P010, DRM_FORMAT_P010, DRM_FORMAT_MOD_LINEAR },
#endif
#if defined(V4L2_PIX_FMT_NV12_COL128) && defined(V4L2_PIX_FMT_NV12_10_COL128)
{
.pixelformat = V4L2_PIX_FMT_NV12_COL128,
.sw_format = AV_PIX_FMT_NONE,
.drm_format = DRM_FORMAT_NV12,
.format_modifier = DRM_FORMAT_MOD_BROADCOM_SAND128,
},
#if defined(DRM_FORMAT_P030)
{
.pixelformat = V4L2_PIX_FMT_NV12_10_COL128,
.sw_format = AV_PIX_FMT_NONE,
.drm_format = DRM_FORMAT_P030,
.format_modifier = DRM_FORMAT_MOD_BROADCOM_SAND128,
},
#endif
#endif
#if defined(V4L2_PIX_FMT_YUV420_10_AFBC_16X16_SPLIT)
{
.pixelformat = V4L2_PIX_FMT_YUV420_10_AFBC_16X16_SPLIT,
.sw_format = AV_PIX_FMT_NONE,
.drm_format = DRM_FORMAT_YUV420_10BIT,
.format_modifier = DRM_FORMAT_MOD_ARM_AFBC(AFBC_FORMAT_MOD_BLOCK_SIZE_16x16 |
AFBC_FORMAT_MOD_SPARSE |
AFBC_FORMAT_MOD_SPLIT),
},
#endif
#if defined(V4L2_PIX_FMT_YUV420_8_AFBC_16X16_SPLIT)
{
.pixelformat = V4L2_PIX_FMT_YUV420_8_AFBC_16X16_SPLIT,
.sw_format = AV_PIX_FMT_NONE,
.drm_format = DRM_FORMAT_YUV420_8BIT,
.format_modifier = DRM_FORMAT_MOD_ARM_AFBC(AFBC_FORMAT_MOD_BLOCK_SIZE_16x16 |
AFBC_FORMAT_MOD_SPARSE |
AFBC_FORMAT_MOD_SPLIT),
},
#endif
};
enum AVPixelFormat ff_v4l2_request_get_sw_format(struct v4l2_format *format)
{
uint32_t pixelformat = V4L2_TYPE_IS_MULTIPLANAR(format->type) ?
format->fmt.pix_mp.pixelformat :
format->fmt.pix.pixelformat;
for (int i = 0; i < FF_ARRAY_ELEMS(v4l2_request_capture_pixelformats); i++) {
if (pixelformat == v4l2_request_capture_pixelformats[i].pixelformat)
return v4l2_request_capture_pixelformats[i].sw_format;
}
return AV_PIX_FMT_NONE;
}
int ff_v4l2_request_set_drm_descriptor(V4L2RequestFrameDescriptor *framedesc,
struct v4l2_format *format)
{
AVDRMFrameDescriptor *desc = &framedesc->base;
AVDRMLayerDescriptor *layer = &desc->layers[0];
uint32_t pixelformat = V4L2_TYPE_IS_MULTIPLANAR(format->type) ?
format->fmt.pix_mp.pixelformat :
format->fmt.pix.pixelformat;
// Set drm format and format modifier
layer->format = 0;
for (int i = 0; i < FF_ARRAY_ELEMS(v4l2_request_capture_pixelformats); i++) {
if (pixelformat == v4l2_request_capture_pixelformats[i].pixelformat) {
layer->format = v4l2_request_capture_pixelformats[i].drm_format;
desc->objects[0].format_modifier =
v4l2_request_capture_pixelformats[i].format_modifier;
break;
}
}
if (!layer->format)
return AVERROR(ENOENT);
desc->nb_objects = 1;
desc->objects[0].fd = framedesc->capture.fd;
desc->objects[0].size = framedesc->capture.size;
desc->nb_layers = 1;
layer->nb_planes = 1;
layer->planes[0].object_index = 0;
layer->planes[0].offset = 0;
layer->planes[0].pitch = V4L2_TYPE_IS_MULTIPLANAR(format->type) ?
format->fmt.pix_mp.plane_fmt[0].bytesperline :
format->fmt.pix.bytesperline;
// AFBC formats only use 1 plane, remaining use 2 planes
if ((desc->objects[0].format_modifier >> 56) != DRM_FORMAT_MOD_VENDOR_ARM) {
layer->nb_planes = 2;
layer->planes[1].object_index = 0;
layer->planes[1].offset = layer->planes[0].pitch *
(V4L2_TYPE_IS_MULTIPLANAR(format->type) ?
format->fmt.pix_mp.height :
format->fmt.pix.height);
layer->planes[1].pitch = layer->planes[0].pitch;
}
#if defined(V4L2_PIX_FMT_NV12_COL128) && defined(V4L2_PIX_FMT_NV12_10_COL128)
// Raspberry Pi formats need special handling
if (pixelformat == V4L2_PIX_FMT_NV12_COL128 ||
pixelformat == V4L2_PIX_FMT_NV12_10_COL128) {
desc->objects[0].format_modifier =
DRM_FORMAT_MOD_BROADCOM_SAND128_COL_HEIGHT(layer->planes[0].pitch);
layer->planes[1].offset = 128 *
(V4L2_TYPE_IS_MULTIPLANAR(format->type) ?
format->fmt.pix_mp.height :
format->fmt.pix.height);
layer->planes[0].pitch = (V4L2_TYPE_IS_MULTIPLANAR(format->type) ?
format->fmt.pix_mp.width :
format->fmt.pix.width);
if (pixelformat == V4L2_PIX_FMT_NV12_10_COL128)
layer->planes[0].pitch *= 2;
layer->planes[1].pitch = layer->planes[0].pitch;
}
#endif
return 0;
}
static int v4l2_request_set_format(AVCodecContext *avctx,
enum v4l2_buf_type type,
uint32_t pixelformat,
uint32_t buffersize)
{
V4L2RequestContext *ctx = v4l2_request_context(avctx);
struct v4l2_format format = {
.type = type,
};
if (V4L2_TYPE_IS_MULTIPLANAR(type)) {
format.fmt.pix_mp.width = avctx->coded_width;
format.fmt.pix_mp.height = avctx->coded_height;
format.fmt.pix_mp.pixelformat = pixelformat;
format.fmt.pix_mp.plane_fmt[0].sizeimage = buffersize;
format.fmt.pix_mp.num_planes = 1;
} else {
format.fmt.pix.width = avctx->coded_width;
format.fmt.pix.height = avctx->coded_height;
format.fmt.pix.pixelformat = pixelformat;
format.fmt.pix.sizeimage = buffersize;
}
if (ioctl(ctx->video_fd, VIDIOC_S_FMT, &format) < 0)
return AVERROR(errno);
return 0;
}
static int v4l2_request_select_capture_format(AVCodecContext *avctx)
{
V4L2RequestContext *ctx = v4l2_request_context(avctx);
enum v4l2_buf_type type = ctx->format.type;
struct v4l2_format format = {
.type = type,
};
struct v4l2_fmtdesc fmtdesc = {
.index = 0,
.type = type,
};
uint32_t pixelformat;
// Get the driver preferred (or default) format
if (ioctl(ctx->video_fd, VIDIOC_G_FMT, &format) < 0)
return AVERROR(errno);
pixelformat = V4L2_TYPE_IS_MULTIPLANAR(type) ?
format.fmt.pix_mp.pixelformat :
format.fmt.pix.pixelformat;
// Use the driver preferred format when it is supported
for (int i = 0; i < FF_ARRAY_ELEMS(v4l2_request_capture_pixelformats); i++) {
if (pixelformat == v4l2_request_capture_pixelformats[i].pixelformat)
return v4l2_request_set_format(avctx, type, pixelformat, 0);
}
// Otherwise, use first format that is supported
while (ioctl(ctx->video_fd, VIDIOC_ENUM_FMT, &fmtdesc) >= 0) {
for (int i = 0; i < FF_ARRAY_ELEMS(v4l2_request_capture_pixelformats); i++) {
if (fmtdesc.pixelformat == v4l2_request_capture_pixelformats[i].pixelformat)
return v4l2_request_set_format(avctx, type, fmtdesc.pixelformat, 0);
}
fmtdesc.index++;
}
return AVERROR(errno);
}
static int v4l2_request_try_framesize(AVCodecContext *avctx,
uint32_t pixelformat)
{
V4L2RequestContext *ctx = v4l2_request_context(avctx);
struct v4l2_frmsizeenum frmsize = {
.index = 0,
.pixel_format = pixelformat,
};
// Enumerate and check if frame size is supported
while (ioctl(ctx->video_fd, VIDIOC_ENUM_FRAMESIZES, &frmsize) >= 0) {
if (frmsize.type == V4L2_FRMSIZE_TYPE_DISCRETE &&
frmsize.discrete.width == avctx->coded_width &&
frmsize.discrete.height == avctx->coded_height) {
return 0;
} else if ((frmsize.type == V4L2_FRMSIZE_TYPE_STEPWISE ||
frmsize.type == V4L2_FRMSIZE_TYPE_CONTINUOUS) &&
avctx->coded_width <= frmsize.stepwise.max_width &&
avctx->coded_height <= frmsize.stepwise.max_height &&
avctx->coded_width % frmsize.stepwise.step_width == 0 &&
avctx->coded_height % frmsize.stepwise.step_height == 0) {
return 0;
}
frmsize.index++;
}
return AVERROR(errno);
}
static int v4l2_request_try_format(AVCodecContext *avctx,
enum v4l2_buf_type type,
uint32_t pixelformat)
{
V4L2RequestContext *ctx = v4l2_request_context(avctx);
struct v4l2_fmtdesc fmtdesc = {
.index = 0,
.type = type,
};
// Enumerate and check if format is supported
while (ioctl(ctx->video_fd, VIDIOC_ENUM_FMT, &fmtdesc) >= 0) {
if (fmtdesc.pixelformat == pixelformat)
return 0;
fmtdesc.index++;
}
return AVERROR(errno);
}
static int v4l2_request_probe_video_device(const char *path,
AVCodecContext *avctx,
uint32_t pixelformat,
uint32_t buffersize,
struct v4l2_ext_control *control,
int count)
{
V4L2RequestContext *ctx = v4l2_request_context(avctx);
struct v4l2_capability capability;
struct v4l2_create_buffers buffers = {
.count = 0,
.memory = V4L2_MEMORY_MMAP,
};
unsigned int capabilities;
int ret;
/*
* Open video device in non-blocking mode to support decoding using
* multiple queued requests, required for e.g. multi stage decoding.
*/
ctx->video_fd = open(path, O_RDWR | O_NONBLOCK);
if (ctx->video_fd < 0) {
av_log(avctx, AV_LOG_ERROR, "Failed to open video device %s: %s (%d)\n",
path, strerror(errno), errno);
return AVERROR(errno);
}
// Query capabilities of the video device
if (ioctl(ctx->video_fd, VIDIOC_QUERYCAP, &capability) < 0) {
av_log(avctx, AV_LOG_ERROR, "Failed to query capabilities of %s: %s (%d)\n",
path, strerror(errno), errno);
ret = AVERROR(errno);
goto fail;
}
// Use device capabilities when needed
if (capability.capabilities & V4L2_CAP_DEVICE_CAPS)
capabilities = capability.device_caps;
else
capabilities = capability.capabilities;
// Ensure streaming is supported on the video device
if ((capabilities & V4L2_CAP_STREAMING) != V4L2_CAP_STREAMING) {
av_log(ctx, AV_LOG_VERBOSE, "Device %s is missing streaming capability\n", path);
ret = AVERROR(EINVAL);
goto fail;
}
// Ensure multi- or single-planar API can be used
if ((capabilities & V4L2_CAP_VIDEO_M2M_MPLANE) == V4L2_CAP_VIDEO_M2M_MPLANE) {
ctx->output_type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
ctx->format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
} else if ((capabilities & V4L2_CAP_VIDEO_M2M) == V4L2_CAP_VIDEO_M2M) {
ctx->output_type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
ctx->format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
} else {
av_log(ctx, AV_LOG_VERBOSE, "Device %s is missing mem2mem capability\n", path);
ret = AVERROR(EINVAL);
goto fail;
}
// Query output buffer capabilities
buffers.format.type = ctx->output_type;
if (ioctl(ctx->video_fd, VIDIOC_CREATE_BUFS, &buffers) < 0) {
av_log(avctx, AV_LOG_ERROR,
"Failed to query output buffer capabilities of %s: %s (%d)\n",
path, strerror(errno), errno);
ret = AVERROR(errno);
goto fail;
}
// Ensure requests can be used
if ((buffers.capabilities & V4L2_BUF_CAP_SUPPORTS_REQUESTS) !=
V4L2_BUF_CAP_SUPPORTS_REQUESTS) {
av_log(ctx, AV_LOG_VERBOSE, "Device %s is missing support for requests\n", path);
ret = AVERROR(EINVAL);
goto fail;
}
// Ensure the codec pixelformat can be used
ret = v4l2_request_try_format(avctx, ctx->output_type, pixelformat);
if (ret < 0) {
av_log(ctx, AV_LOG_VERBOSE, "Device %s is missing support for pixelformat %s\n",
path, av_fourcc2str(pixelformat));
goto fail;
}
// Ensure frame size is supported, when driver support ENUM_FRAMESIZES
ret = v4l2_request_try_framesize(avctx, pixelformat);
if (ret < 0 && ret != AVERROR(ENOTTY)) {
av_log(ctx, AV_LOG_VERBOSE,
"Device %s is missing support for frame size %dx%d of pixelformat %s\n",
path, avctx->coded_width, avctx->coded_height, av_fourcc2str(pixelformat));
goto fail;
}
// Set the codec pixelformat and output buffersize to be used
ret = v4l2_request_set_format(avctx, ctx->output_type, pixelformat, buffersize);
if (ret < 0) {
av_log(avctx, AV_LOG_ERROR,
"Failed to set output pixelformat %s of %s: %s (%d)\n",
av_fourcc2str(pixelformat), path, strerror(errno), errno);
goto fail;
}
/*
* Set any codec specific controls that can help assist the driver
* make a decision on what capture buffer format can be used.
*/
ret = ff_v4l2_request_set_controls(avctx, control, count);
if (ret < 0)
goto fail;
// Select a capture buffer format known to the hwaccel
ret = v4l2_request_select_capture_format(avctx);
if (ret < 0) {
av_log(avctx, AV_LOG_VERBOSE,
"Failed to select a capture format for %s of %s: %s (%d)\n",
av_fourcc2str(pixelformat), path, strerror(errno), errno);
goto fail;
}
// Check codec specific controls, e.g. profile and level
if (ctx->post_probe) {
ret = ctx->post_probe(avctx);
if (ret < 0)
goto fail;
}
// All tests passed, video device should be capable
return 0;
fail:
if (ctx->video_fd >= 0) {
close(ctx->video_fd);
ctx->video_fd = -1;
}
return ret;
}
static int v4l2_request_probe_video_devices(struct udev *udev,
AVCodecContext *avctx,
uint32_t pixelformat,
uint32_t buffersize,
struct v4l2_ext_control *control,
int count)
{
V4L2RequestContext *ctx = v4l2_request_context(avctx);
struct media_device_info device_info;
struct media_v2_topology topology = {0};
struct media_v2_interface *interfaces;
struct udev_device *device;
const char *path;
dev_t devnum;
int ret;
if (ioctl(ctx->media_fd, MEDIA_IOC_DEVICE_INFO, &device_info) < 0)
return AVERROR(errno);
if (ioctl(ctx->media_fd, MEDIA_IOC_G_TOPOLOGY, &topology) < 0) {
av_log(avctx, AV_LOG_ERROR, "Failed to get media topology: %s (%d)\n",
strerror(errno), errno);
return AVERROR(errno);
}
if (!topology.num_interfaces)
return AVERROR(ENOENT);
interfaces = av_calloc(topology.num_interfaces, sizeof(struct media_v2_interface));
if (!interfaces)
return AVERROR(ENOMEM);
topology.ptr_interfaces = (__u64)(uintptr_t)interfaces;
if (ioctl(ctx->media_fd, MEDIA_IOC_G_TOPOLOGY, &topology) < 0) {
av_log(avctx, AV_LOG_ERROR, "Failed to get media topology: %s (%d)\n",
strerror(errno), errno);
ret = AVERROR(errno);
goto fail;
}
ret = AVERROR(ENOENT);
for (int i = 0; i < topology.num_interfaces; i++) {
if (interfaces[i].intf_type != MEDIA_INTF_T_V4L_VIDEO)
continue;
devnum = makedev(interfaces[i].devnode.major, interfaces[i].devnode.minor);
device = udev_device_new_from_devnum(udev, 'c', devnum);
if (!device)
continue;
path = udev_device_get_devnode(device);
if (path)
ret = v4l2_request_probe_video_device(path, avctx, pixelformat,
buffersize, control, count);
udev_device_unref(device);
// Stop when we have found a capable video device
if (!ret) {
av_log(avctx, AV_LOG_INFO,
"Using V4L2 media driver %s (%u.%u.%u) for %s\n",
device_info.driver,
device_info.driver_version >> 16,
(device_info.driver_version >> 8) & 0xff,
device_info.driver_version & 0xff,
av_fourcc2str(pixelformat));
break;
}
}
fail:
av_free(interfaces);
return ret;
}
static int v4l2_request_probe_media_device(struct udev_device *device,
AVCodecContext *avctx,
uint32_t pixelformat,
uint32_t buffersize,
struct v4l2_ext_control *control,
int count)
{
V4L2RequestContext *ctx = v4l2_request_context(avctx);
const char *path;
int ret;
path = udev_device_get_devnode(device);
if (!path)
return AVERROR(ENODEV);
// Open enumerated media device
ctx->media_fd = open(path, O_RDWR);
if (ctx->media_fd < 0) {
av_log(avctx, AV_LOG_ERROR, "Failed to open media device %s: %s (%d)\n",
path, strerror(errno), errno);
return AVERROR(errno);
}
// Probe video devices of current media device
ret = v4l2_request_probe_video_devices(udev_device_get_udev(device),
avctx, pixelformat,
buffersize, control, count);
// Cleanup when no capable video device was found
if (ret < 0) {
close(ctx->media_fd);
ctx->media_fd = -1;
}
return ret;
}
static int v4l2_request_probe_media_devices(struct udev *udev,
AVCodecContext *avctx,
uint32_t pixelformat,
uint32_t buffersize,
struct v4l2_ext_control *control,
int count)
{
struct udev_enumerate *enumerate;
struct udev_list_entry *devices;
struct udev_list_entry *entry;
struct udev_device *device;
int ret;
enumerate = udev_enumerate_new(udev);
if (!enumerate)
return AVERROR(ENOMEM);
udev_enumerate_add_match_subsystem(enumerate, "media");
udev_enumerate_scan_devices(enumerate);
devices = udev_enumerate_get_list_entry(enumerate);
ret = AVERROR(ENOENT);
udev_list_entry_foreach(entry, devices) {
const char *path = udev_list_entry_get_name(entry);
if (!path)
continue;
device = udev_device_new_from_syspath(udev, path);
if (!device)
continue;
// Probe media device for a capable video device
ret = v4l2_request_probe_media_device(device, avctx, pixelformat,
buffersize, control, count);
udev_device_unref(device);
// Stop when we have found a capable media and video device
if (!ret)
break;
}
udev_enumerate_unref(enumerate);
return ret;
}
int ff_v4l2_request_probe(AVCodecContext *avctx,
uint32_t pixelformat, uint32_t buffersize,
struct v4l2_ext_control *control, int count)
{
V4L2RequestContext *ctx = v4l2_request_context(avctx);
struct udev *udev;
int ret;
udev = udev_new();
if (!udev)
return AVERROR(ENOMEM);
if (ctx->media_fd >= 0) {
// Probe video devices of current media device
ret = v4l2_request_probe_video_devices(udev, avctx, pixelformat,
buffersize, control, count);
} else {
// Probe all media devices (auto-detect)
ret = v4l2_request_probe_media_devices(udev, avctx, pixelformat,
buffersize, control, count);
}
udev_unref(udev);
return ret;
}