[mythtv] [mythtv-commits] Ticket #2198: Transcode treats some 1080i streams as 1088 and puts a grey line at the bottom after resizing

[Steven Adeff]

On 8/18/06, MythTV <mythtv at cvs.mythtv.org> wrote:
> #2198: Transcode treats some 1080i streams as 1088 and puts a grey line at the
> bottom after resizing
> -----------------------------+----------------------------------------------
>  Reporter:  wagspat at iit.edu  |        Owner:  cpinkham
>      Type:  defect           |       Status:  new
>  Priority:  minor            |    Milestone:
> Component:  mythtv           |      Version:  0.19
>  Severity:  low              |   Resolution:
> -----------------------------+----------------------------------------------
> Comment (by wagspat at iit.edu):
>
>  It looks like the way to solve this may be to call img_resize_full_init
>  instead of img_resize_init in transcode.cpp.  This allows the
>  specification of the borders around an image that should be cropped off
>  the image.  I'm attaching a patch against the 0.19-fixes branch that seems
>  to work for the 1080i use case here.  Hopefully this provides some good
>  direction.


The issue is that 1080i is really 1920x1088 due to the MPEG 16x16
macroblock. The MPEG header is supposed to carry a flag that tells the
player to ignore tha last 8 lines. So what MythTranscode needs to do
for 1080i/p is to encode at 1920x1088 but set the flag for 1920x1080.
This will need to be done for any format that uses a 16x16 macroblock.
Check the MPlayer dev list archive for more information on this.



-- 
Steve
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