Hi Pawel,

Is it valid when output size is 0 during video encoding?

If output size 0 is invalid, we can easily add an ASSERT in BitstreamBufferReady().
Otherwise, we have to add another parameter to the client or implement another new client.

Yes, output size=0 may indicate that the encoder did not fit into the bitrate budget and decided to drop the frame.

We talked to Pawel offline.
- It is valid to have an size 0 output buffer during encoding. For example,
if an encoder decides it can't fit in the bitrate window, it can decide to drop a frame. But since we always expect a buffer for each source frame, we send an empty buffer.
- Encoder should not generate an output if there's no input even given to the encoder.

Henry. Please go ahead and add the test. I think Franky doesn't have time to finish it before he's gone.

Friendly ping. We should add this for M56.

Ping.

https://codereview.chromium.org/2472923002

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a4b8c15b3b178281c8f4d92afc3b38ff607480f6

commit a4b8c15b3b178281c8f4d92afc3b38ff607480f6
Author: henryhsu <henryhsu@chromium.org>
Date: Mon Nov 07 06:32:33 2016

Add a test case to make sure no output before getting any input

This is used to test crbug.com/641600.
VEA driver should not return an output buffer without any input.

BUG= 648861 
TEST=test on device.

Review-Url: https://codereview.chromium.org/2472923002
Cr-Commit-Position: refs/heads/master@{#430223}

[modify] https://crrev.com/a4b8c15b3b178281c8f4d92afc3b38ff607480f6/media/gpu/video_encode_accelerator_unittest.cc

Verified