New issue
Advanced search Search tips
Note: Color blocks (like or ) mean that a user may not be available. Tooltip shows the reason.

Issue 879263 link

Starred by 2 users

Issue metadata

Status: Fixed
Owner:
Last visit > 30 days ago
Closed: Dec 14
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: ----
Pri: 3
Type: Bug



Sign in to add a comment

/media/test/data/bear-av1.webm is not spec compliant

Project Member Reported by kqyang@chromium.org, Aug 30

Issue description

AOM AV1 codec mapping in Matroska/WebM specification [1] states that CodecPrivate is mandatory:

EBML Path: \Segment\Tracks\TrackEntry\CodecPrivate | Mandatory: Yes

It is not present in file /media/test/data/bear-av1.webm. Should that be fixed?

There is a related issue in /media/test/data/bear-av1.mp4, which has incorrect AV1CodecConfiguration box (chroma_sample_position is set to 0 instead of 2).

[1] https://github.com/Matroska-Org/matroska-specification/blob/av1-mappin/codec/av1.md#codecprivate-1
 
Cc: -tomfinegan@chromium.org dalecur...@chromium.org
Owner: tomfinegan@chromium.org
Status: Assigned (was: Untriaged)
Cc: xhw...@chromium.org
FWIW, this is blocking me to get an encrypted av1 webm file using shaka packager for testing :)
Status: Started (was: Assigned)
fyi. FFmpeg has added CodecPrivate generation in WebM a few weeks ago: https://git.ffmpeg.org/gitweb/ffmpeg.git/commitdiff/4755b6e6d194b0a0fb72957cd3dc0eaf7b2375f7.
@kqyang

> There is a related issue in /media/test/data/bear-av1.mp4, which has incorrect AV1CodecConfiguration box (chroma_sample_position is set to 0 instead of 2).

Why do you believe the value should be 2? 0, aka CSP_UNKNOWN, is valid for 8-bit I420 when the encoder does not know the value.

> fyi. FFmpeg has added CodecPrivate generation in WebM a few weeks ago: https://git.ffmpeg.org/gitweb/ffmpeg.git/commitdiff/4755b6e6d194b0a0fb72957cd3dc0eaf7b2375f7.

Thanks, but aomenc handles this already. 
> Why do you believe the value should be 2? 0, aka CSP_UNKNOWN, is valid for 8-bit I420 when the encoder does not know the value.

It was extracted from the bitstream, but it is possible that I could have made a mistake. I will take a look at it later.
Project Member

Comment 7 by bugdroid1@chromium.org, Oct 18

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b430c9d0c83a00fef1ecdefd8c0d83f935c68b24

commit b430c9d0c83a00fef1ecdefd8c0d83f935c68b24
Author: Tom Finegan <tomfinegan@google.com>
Date: Thu Oct 18 00:59:19 2018

media: Update AV1 WebM files.

Re-encoded for spec compliance. Previous versions omitted the
Codec Private.

BUG= 879263 
R=dalecurtis

Change-Id: I466e15886bba2b975b4b8b93a15cefb604f93057
Reviewed-on: https://chromium-review.googlesource.com/c/1287091
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Commit-Queue: Tom Finegan <tomfinegan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600625}
[modify] https://crrev.com/b430c9d0c83a00fef1ecdefd8c0d83f935c68b24/media/test/data/README.md
[modify] https://crrev.com/b430c9d0c83a00fef1ecdefd8c0d83f935c68b24/media/test/data/bear-av1-480x360.webm
[modify] https://crrev.com/b430c9d0c83a00fef1ecdefd8c0d83f935c68b24/media/test/data/bear-av1-640x480.webm
[modify] https://crrev.com/b430c9d0c83a00fef1ecdefd8c0d83f935c68b24/media/test/data/bear-av1.webm
[modify] https://crrev.com/b430c9d0c83a00fef1ecdefd8c0d83f935c68b24/media/test/pipeline_integration_test.cc

Status: Fixed (was: Started)
Re https://bugs.chromium.org/p/chromium/issues/detail?id=879263#c5,

You are right. The chroma sampling position is 0 in the bitstream.


Sign in to add a comment