VAAPI VDA H264 Encoder: explicitly set max_num_reorder_frames to 0 in VUI.

VAAPI VDA H264 Encoder: explicitly set max_num_reorder_frames to 0 in VUI.

Set max_num_reorder_frames to allow the decoder to output pictures early.

BUG=446627
TEST=video_encode_accelerator_unittest

Committed: https://crrev.com/8e37c0b62f039f48abec63409f01965081f8d8b4
Cr-Commit-Position: refs/heads/master@{#311504}

[hshi1, 2015-01-07 23:55:24]

hshi@chromium.org changed reviewers:
+ posciak@chromium.org

[hshi1, 2015-01-07 23:55:25]

PTAL, thanks!

[hshi1, 2015-01-08 18:14:00]

hshi@chromium.org changed reviewers:
+ holmer@chromium.org

[hshi1, 2015-01-08 18:14:00]

+holmer as well.

Correctly setting the max_num_reordering_frame_ field has also the benefit of
much lower end-to-end latency because the receiver can output pictures about
12-15 frames earlier, on average.

[holmer, 2015-01-09 15:31:48]

On 2015/01/08 18:14:00, hshi1 wrote:
> +holmer as well.
> 
> Correctly setting the max_num_reordering_frame_ field has also the benefit of
> much lower end-to-end latency because the receiver can output pictures about
> 12-15 frames earlier, on average.

lgtm, but this code is completely new to me so we need Pawel's review as well.

[Pawel Osciak, 2015-01-13 13:59:44]

https://codereview.chromium.org/794433005/diff/1/content/common/gpu/media/vaa...
File content/common/gpu/media/vaapi_video_encode_accelerator.cc (right):

https://codereview.chromium.org/794433005/diff/1/content/common/gpu/media/vaa...
content/common/gpu/media/vaapi_video_encode_accelerator.cc:979:
packed_sps_.AppendUE(0);        // max_bits_per_mb_denom
I think we probably want to say 2 and 1, respectively, for denoms.
Otherwise we divide by zero. And 2 and 1 seem to be the defaults per spec...

[hshi1, 2015-01-13 18:50:19]

https://codereview.chromium.org/794433005/diff/1/content/common/gpu/media/vaa...
File content/common/gpu/media/vaapi_video_encode_accelerator.cc (right):

https://codereview.chromium.org/794433005/diff/1/content/common/gpu/media/vaa...
content/common/gpu/media/vaapi_video_encode_accelerator.cc:979:
packed_sps_.AppendUE(0);        // max_bits_per_mb_denom
On 2015/01/13 13:59:44, Pawel Osciak wrote:
> I think we probably want to say 2 and 1, respectively, for denoms.
> Otherwise we divide by zero. And 2 and 1 seem to be the defaults per spec...

Done.

[Pawel Osciak, 2015-01-14 02:04:33]

lgtm % nits

https://codereview.chromium.org/794433005/diff/20001/content/common/gpu/media...
File content/common/gpu/media/vaapi_video_encode_accelerator.cc (right):

https://codereview.chromium.org/794433005/diff/20001/content/common/gpu/media...
content/common/gpu/media/vaapi_video_encode_accelerator.cc:975:
packed_sps_.AppendBool(true);   // bitstream_restriction_flag
Nit: per coding style "end-of-line comments should be separated from the code by
2 spaces."

https://codereview.chromium.org/794433005/diff/20001/content/common/gpu/media...
content/common/gpu/media/vaapi_video_encode_accelerator.cc:983: // Disable frame
reordering.
Nit: this does not disable frame reordering. We "disable" reordering by actually
not doing frame reordering in the encoding process in this whole class. Flipping
this flag would not enable it.

Please update the comment to say so.

[hshi1, 2015-01-14 02:27:55]

https://codereview.chromium.org/794433005/diff/20001/content/common/gpu/media...
File content/common/gpu/media/vaapi_video_encode_accelerator.cc (right):

https://codereview.chromium.org/794433005/diff/20001/content/common/gpu/media...
content/common/gpu/media/vaapi_video_encode_accelerator.cc:975:
packed_sps_.AppendBool(true);   // bitstream_restriction_flag
On 2015/01/14 02:04:33, Pawel Osciak wrote:
> Nit: per coding style "end-of-line comments should be separated from the code
by
> 2 spaces."

Done.

https://codereview.chromium.org/794433005/diff/20001/content/common/gpu/media...
content/common/gpu/media/vaapi_video_encode_accelerator.cc:983: // Disable frame
reordering.
On 2015/01/14 02:04:33, Pawel Osciak wrote:
> Nit: this does not disable frame reordering. We "disable" reordering by
actually
> not doing frame reordering in the encoding process in this whole class.
Flipping
> this flag would not enable it.
> 
> Please update the comment to say so.

Done.

[hshi1, 2015-01-14 17:46:18]

The CQ bit was checked by hshi@chromium.org

[commit-bot: I haz the power, 2015-01-14 17:47:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/794433005/40001

[commit-bot: I haz the power, 2015-01-14 17:48:25]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-01-14 17:49:28]

Patchset 3 (id:??) landed as
https://crrev.com/8e37c0b62f039f48abec63409f01965081f8d8b4
Cr-Commit-Position: refs/heads/master@{#311504}