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[v2,media] s5p-mfc: Don't try to resubmit VP8 bitstream buffer for decode.

Message ID 1399889804-4225-1-git-send-email-arun.kk@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Arun Kumar K May 12, 2014, 10:16 a.m. UTC 
From: Pawel Osciak <posciak@chromium.org>

Currently, for formats that are not H264, MFC driver will check
the consumed stream size returned by the firmware and, based on that,
will try to decide whether the bitstream buffer contained more than
one frame. If the size of the buffer is larger than the consumed
stream, it assumes that there are more frames in the buffer and that the
buffer should be resubmitted for decode. This rarely works though and
actually introduces problems, because:

- v7 firmware will always return consumed stream size equal to whatever
the driver passed to it when running decode (which is the size of the whole
buffer), which means we will never try to resubmit, because the firmware
will always tell us that it consumed all the data we passed to it;

- v6 firmware will return the number of consumed bytes, but will not
include the padding ("stuffing") bytes that are allowed after the frame
in VP8. Since there is no way of figuring out how many of those bytes
follow the frame without getting the frame size from IVF headers (or
somewhere else, but not from the stream itself), the driver tries to guess that
padding size is not larger than 4 bytes, which is not always true;

The only way to make it work is to queue only one frame per buffer from
userspace and the check in the kernel is useless and wrong for VP8.
So adding VP8 also along with H264 to disallow re-submitting of buffer
back to hardware for decode.

Signed-off-by: Pawel Osciak <posciak@chromium.org>
Signed-off-by: Arun Kumar K <arun.kk@samsung.com>
---
Changes from v1
- Made the condition to specifically add VP8 case only
  suggested by Kamil.
---
 drivers/media/platform/s5p-mfc/s5p_mfc.c |    1 +
 1 file changed, 1 insertion(+)
diff mbox

Patch

diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c
index 0f796ad..2d7d1ae 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -382,6 +382,7 @@  static void s5p_mfc_handle_frame(struct s5p_mfc_ctx *ctx,
 		ctx->consumed_stream += s5p_mfc_hw_call(dev->mfc_ops,
 						get_consumed_stream, dev);
 		if (ctx->codec_mode != S5P_MFC_CODEC_H264_DEC &&
+			ctx->codec_mode != S5P_MFC_CODEC_VP8_DEC &&
 			ctx->consumed_stream + STUFF_BYTE <
 			src_buf->b->v4l2_planes[0].bytesused) {
 			/* Run MFC again on the same buffer */