invalid / distorded frames on VP6F-encoded contents (FLV) (Bug #2815)

Added by Guillaume Ferry about 12 years ago. Updated about 12 years ago.

Status:Done Start date:2013-02-19
Priority:Normal Due date:
Assignee:Vadim Pisarevsky % Done:

0%
Category:highgui-video
Target version:2.4.4
Affected version:2.4.3 Operating System:
Difficulty: HW Platform:
Pull request:

Description

Hi,

I'm running OpenCV 2.4.3 on an up-to-date Kubuntu 12.10 (64bits), and I've noticed a decoding while processing a valid FLV video file, that contains a VP6F video stream.
This video runs fine through VLC, mplayer, ffplay, but I can't obtain valid frames using OpenCV : all of them are being displayed distorted (cf. attached picture)
There are no issues on this topic reported so far (at least, I couldn't find them), so here it goes.

I'll also attach a link to download the sample FLV file shortly, since it's around 20Mb

Best regards,
Guillaume.

PS : the attached picture actually represents one of the first frames loaded with imread() and outputted with imwrite()

shot_0001.jpg (236.4 kB) Guillaume Ferry, 2013-02-19 11:01 am

Associated revisions

Revision e3803f99
Added by Guillaume Ferry about 12 years ago

fix for OpenCV issue #2815

- libavcodec issue
- some decoders alter AVCodecContext width/height values, in a wrong way
- eg. in issue 2815, vp6f decoder changes these values, resulting in distorted / invalid frames
- this patch forces default AVCodecContext values

Revision d31a0eab
Added by Roman Donchenko over 10 years ago

Merge pull request #2815 from Aletheios:Bugfix#3705

History

#1
Updated by Guillaume Ferry about 12 years ago

Here is a direct link for the FLV video:
https://www.dropbox.com/s/2iu30fh02yjsntj/50829739.flv

#2
Updated by Anna Kogan about 12 years ago

Hello Guillaume,
Thank you for reporting the issue! If you could work on a fix and provide it as a pull request for the '2.4' branch, that would help a lot!

#3
Updated by Guillaume Ferry about 12 years ago

Hi Anna,

I'll have a look on it, sure.

Regards,
Guillaume

#4
Updated by Guillaume Ferry about 12 years ago

Okay Anna,

I've just submitted a tiny pull request that adresses this issue (ID #510)
I can now process all these special FLV files perfectly, and so far, no regressions can be observed with other video types

Regards,
Guillaume.

#5
Updated by Guillaume Ferry about 12 years ago

By the way, here are some ffmpeg tickets that reference this issue:

https://ffmpeg.org/trac/ffmpeg/ticket/1386
https://ffmpeg.org/trac/ffmpeg/ticket/2268

#6
Updated by Anna Kogan about 12 years ago

Wow, so soon! Thank you for the pull request=)

#7
Updated by Andrey Kamaev about 12 years ago

Fix is pushed to 2.4

  • Target version set to 2.4.4
  • Status changed from Open to Done

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