[mythtv-users] Scrambled preview image after HandBrakeCLI transcode

[Dan Wilga]

On 5/19/14, 2:14 PM, John Pilkington wrote:
> On 19/05/14 14:44, David H. Johnson, III wrote:
>> I'm having the same issue as Mark
>> (http://www.gossamer-threads.com/lists/mythtv/users/555356) --
>> mythpreviewgen is cranking out scrambled/garbled images (exact symptoms
>> as Mark's) on my HandBrakeCLI-transcoded MP4s.  I tried Mike(mtdean)'s
>> solution and ran
>>
>> mythcommflag --rebuild --file 
>> /var/lib/mythtv/recordings/2002_20140429140000.mp4
>>
>> but still get the same scrambled images.  Am I missing something?  Prior
>> to running mythcommflag, I updated the filename, filesize and transcoded
>> fields for the appropriate record in the recorded table.  Is there
>> anything else I need to update?
>>
>> Thank you,
>> David
>
> I believe there's still a problem with mythcommflag --rebuild and at 
> least some varieties of h264 material.  It may find only a small 
> proportion of the 'keyframes' identified during the original 
> recording.  I don't know if that might affect what you see.  AFAIK the 
> latest on this is here
The cases I've seen of corrupt previews seem to suggest that 
mythpreviewgen is confused about the width of the video frame. The image 
looks skewed diagonally. Perhaps it's due to unusual pixel dimensions 
that are not on a byte or word boundary? I don't have easy access to my 
server right now, so I can't check on this.