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

[Mats Peterson]

On 03/08/2016 01:44 PM, Mats Peterson wrote:
> 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
>
> _______________________________________________

The xxpc chunks are indexed alright. I checked the index in the file. 
Why FFplay will barf on it is another question.

Mats