Hi Philipp,
Thank you for the patch.
On Tuesday, 19 December 2017 10:17:35 EET Philipp Zabel wrote:
> The Microsoft HoloLens Sensors device has two separate frame descriptors
> with the same dimensions, each with a single different frame interval:
Why, oh why ? :-(
> VideoStreaming Interface Descriptor:
> bLength 30
> bDescriptorType 36
> bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
> bFrameIndex 1
> bmCapabilities 0x00
> Still image unsupported
> wWidth 1280
> wHeight 481
> dwMinBitRate 147763200
> dwMaxBitRate 147763200
> dwMaxVideoFrameBufferSize 615680
> dwDefaultFrameInterval 333333
> bFrameIntervalType 1
> dwFrameInterval( 0) 333333
> VideoStreaming Interface Descriptor:
> bLength 30
> bDescriptorType 36
> bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
> bFrameIndex 2
> bmCapabilities 0x00
> Still image unsupported
> wWidth 1280
> wHeight 481
> dwMinBitRate 443289600
> dwMaxBitRate 443289600
> dwMaxVideoFrameBufferSize 615680
> dwDefaultFrameInterval 111111
> bFrameIntervalType 1
> dwFrameInterval( 0) 111111
>
> Skip duplicate dimensions in enum_framesizes, let enum_frameintervals list
> the intervals from both frame descriptors. Change set_streamparm to switch
> to the correct frame index when changing the interval. This enables 90 fps
> capture on a Lenovo Explorer Windows Mixed Reality headset.
>
> Signed-off-by: Philipp Zabel <philipp.zabel@xxxxxxxxx>
> ---
> drivers/media/usb/uvc/uvc_v4l2.c | 66 +++++++++++++++++++++++++++----------
> 1 file changed, 50 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c
> b/drivers/media/usb/uvc/uvc_v4l2.c index 3e7e283a44a8..7d5bf8d56a99 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -373,8 +373,11 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming
> *stream, {
> struct uvc_streaming_control probe;
> struct v4l2_fract timeperframe;
> - uint32_t interval;
> + struct uvc_format *format;
> + struct uvc_frame *frame;
> + __u32 interval, tmp, d, maxd;
You can declare tmp and d inside the loop, it should simplify the code
slightly. Please also avoid naming the variable tmp.
> int ret;
> + int i;
i can be unsigned.
> if (parm->type != stream->type)
> return -EINVAL;
> @@ -396,9 +399,31 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming
> *stream, return -EBUSY;
> }
>
> + format = stream->cur_format;
> + frame = stream->cur_frame;
> probe = stream->ctrl;
> - probe.dwFrameInterval =
> - uvc_try_frame_interval(stream->cur_frame, interval);
> + probe.dwFrameInterval = uvc_try_frame_interval(frame, interval);
> + maxd = abs((__s32)probe.dwFrameInterval - interval);
> +
> + /* Try frames with matching size to find the best frame interval. */
> + for (i = 0; i < format->nframes; i++) {
As a small optimization you can also stop when maxd == 0.
> + if (&format->frame[i] == stream->cur_frame)
> + continue;
> +
> + if (format->frame[i].wWidth != stream->cur_frame->wWidth ||
> + format->frame[i].wHeight != stream->cur_frame->wHeight)
> + continue;
> +
> + tmp = uvc_try_frame_interval(&format->frame[i], interval);
> + d = abs((__s32)tmp - interval);
> + if (d >= maxd)
> + continue;
> +
> + frame = &format->frame[i];
> + probe.bFrameIndex = frame->bFrameIndex;
> + probe.dwFrameInterval = tmp;
> + maxd = d;
> + }
>
> /* Probe the device with the new settings. */
> ret = uvc_probe_video(stream, &probe);
> @@ -408,6 +433,7 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming
> *stream, }
>
> stream->ctrl = probe;
> + stream->cur_frame = frame;
> mutex_unlock(&stream->mutex);
>
> /* Return the actual frame period. */
> @@ -1150,7 +1176,7 @@ static int uvc_ioctl_enum_framesizes(struct file
> *file, void *fh, struct uvc_streaming *stream = handle->stream;
> struct uvc_format *format = NULL;
> struct uvc_frame *frame;
> - int i;
> + int i, index;
Could you declare unrelated variables on separate lines ?
I think index can be unsigned (and it seems i can be as well for that matter).
> /* Look for the given pixel format */
> for (i = 0; i < stream->nformats; i++) {
> @@ -1162,10 +1188,20 @@ static int uvc_ioctl_enum_framesizes(struct file
> *file, void *fh, if (format == NULL)
> return -EINVAL;
>
> - if (fsize->index >= format->nframes)
> + /* Skip duplicate frame sizes */
> + for (i = 0, index = 0; i < format->nframes; i++) {
> + if (i && frame->wWidth == format->frame[i].wWidth &&
> + frame->wHeight == format->frame[i].wHeight)
> + continue;
> + frame = &format->frame[i];
> + if (index == fsize->index)
> + break;
> + index++;
> + }
> +
> + if (i == format->nframes)
> return -EINVAL;
>
> - frame = &format->frame[fsize->index];
> fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
> fsize->discrete.width = frame->wWidth;
> fsize->discrete.height = frame->wHeight;
> @@ -1179,7 +1215,7 @@ static int uvc_ioctl_enum_frameintervals(struct file
> *file, void *fh, struct uvc_streaming *stream = handle->stream;
> struct uvc_format *format = NULL;
> struct uvc_frame *frame = NULL;
> - int i;
> + int i, index, nintervals;
Same comments here.
> /* Look for the given pixel format and frame size */
> for (i = 0; i < stream->nformats; i++) {
> @@ -1191,30 +1227,28 @@ static int uvc_ioctl_enum_frameintervals(struct file
> *file, void *fh, if (format == NULL)
> return -EINVAL;
>
> + index = fival->index;
> for (i = 0; i < format->nframes; i++) {
> if (format->frame[i].wWidth == fival->width &&
> format->frame[i].wHeight == fival->height) {
> frame = &format->frame[i];
> - break;
> + nintervals = frame->bFrameIntervalType ?: 1;
> + if (index < nintervals)
> + break;
> + index -= nintervals;
> }
> }
> - if (frame == NULL)
> + if (i == format->nframes)
> return -EINVAL;
>
> if (frame->bFrameIntervalType) {
> - if (fival->index >= frame->bFrameIntervalType)
> - return -EINVAL;
> -
> fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
> fival->discrete.numerator =
> - frame->dwFrameInterval[fival->index];
> + frame->dwFrameInterval[index];
> fival->discrete.denominator = 10000000;
> uvc_simplify_fraction(&fival->discrete.numerator,
> &fival->discrete.denominator, 8, 333);
> } else {
> - if (fival->index)
> - return -EINVAL;
> -
> fival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
> fival->stepwise.min.numerator = frame->dwFrameInterval[0];
> fival->stepwise.min.denominator = 10000000;
I have to say I dislike the complexity added by this patch, but it's not your
fault. The code itself is probably as clean as it can be :)
--
Regards,
Laurent Pinchart
