[FFmpeg-devel] [PATCH] HWAccel infrastructure

Gwenole Beauchesne gbeauchesne
Wed Feb 18 13:10:54 CET 2009

On Wed, 18 Feb 2009, Michael Niedermayer wrote:

>>>> I am just trying to reuse existing code to know where the current
>>>> slice ends. How could I achieve this purpose otherwise?
>>> how does vdpau do it? a quick look shows no ff_find_start_code() but
>>> i may have missed it
>> VDPAU can offload the whole picture data. VA API specifies this as a
>> per-slice process, i.e. emit all individual slice, one control block
>> at a time (VASliceParameterBufferMPEG2). However, in practise and
>> IIRC, the current Intel implementation does support the once control
>> block at a time approach (akin to NVIDIA's VDPAU implementation) but
>> it's just not specified to work that way. So, I need a way to advance
>> to the next slice, thus determining the actual size of the slice.
> that belongs inside the VA API wraper then, not in mpeg12.c, we wouldnt
> want to slow VDPAU down because of limitations on intels side

That doesn't slow down anything since VDPAU also traverses all slices to 
simply count them.

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