@@ -1964,6 +1964,7 @@ EXTERNAL_LIBRARY_LIST="
libtorch
libtwolame
libuavs3d
+ libudev
libv4l2
libvmaf
libvorbis
@@ -3150,7 +3151,7 @@ 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"
@@ -7177,6 +7178,7 @@ 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
@@ -174,7 +174,7 @@ 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
@@ -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) {
@@ -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 */
new file mode 100644
@@ -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;
+}