[FFmpeg-devel] [PATCH] lavf/avienc: New AVOption write_keyframe_palette

Mats Peterson matsp888 at yahoo.com
Tue Mar 8 13:44:50 CET 2016


On 03/08/2016 01:43 PM, Ronald S. Bultje wrote:
> Hi Mats,
>
> On Mon, Mar 7, 2016 at 8:59 PM, Mats Peterson <
> matsp888-at-yahoo.com at ffmpeg.org> wrote:
>
>> On 03/07/2016 07:48 PM, Mats Peterson wrote:
>>
>>> On 03/07/2016 07:43 PM, Mats Peterson wrote:
>>>
>>>> Here's a somewhat experimental patch with a new AVOption
>>>> write_keyframe_palette that allows you to write the palette to every
>>>> keyframe. It is disabled by default, but it is needed for any file that
>>>> contains palette changes.
>>>>
>>>>
>>> It is needed in order to switch palette properly when seeking, that is.
>>>
>>>
>> It's interesting to note that Windows Media Player doesn't need xxpc
>> chunks at keyframes in order to seek properly in the following original
>> file from Sierra's King's Quest VI. I have of course no idea how they solve
>> that.
>>
>> This original file doesn't work properly in FFplay for some reason. It
>> generates "stream_ptr out of bounds" messages at the locations of the xxpc
>> chunks.
>>
>> File:
>> https://drive.google.com/open?id=0B3_pEBoLs0faaFY0ME92SDA1VEU
>
>
> Please don't wrote so many messages in response to yourself.
>
> If you want, I can look at the file. My assumption is that it either
> indexes or otherwise caches the xxpc chunks so it knows what the last xxpc
> before-or-on each keyframe seekpoint is. That should be trivial to do in
> our demuxer also.
>
> Ronald
> _______________________________________________

It would be nice if you could have a look at it, Ronald, when you have 
the time for it. Yes, I suppose the xxpc chunks might perhaps be 
indexed. In any case, it currently won't play correctly in FFplay. I'll 
try to limit my messages (I have said it before, but I'm fully aware of 
this problem).

Mats



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