On Mon, 28 Jul 2008 08:40:56 -0400, MtTracer <[EMAIL PROTECTED]> wrote:
> Alexander Benz schrieb:
>> Hi there,
>>
>> I'm trying to setup a partly multi threaded video pipeline but my result
>> images come out distorted from time to time.
>> It seems like some lines of the video contain lines from the previous
>> frames ... but I can't find the exact cause. Maybe
>> anyone has experienced a similar effect or knows the answer to this
>> problem.
>>
>> In general, what I do is the following :
>>
>> Open the Mpeg2 video stream (av_open_input_file, avcodec_find_decoder,
>> avcodec_open etc.) then
>>
>> 1. Read a frame from the stream (av_read_frame)
>>
> Do you call av_dup_packet for the read packets in this step? Packets may
> become invalid
> after the next call to av_read_frame if you don't duplicate their data.

Actually its worse than this.  The AVFrame must also be duplicated,  
because some codecs re-use the pixel buffers.  Basically you can only rely  
on having a single AVFrame decoded at a time.  This is only an issue for  
some codecs, though.

>> 2. Decode frame (avcodec_decode_video)
>> 3. Do color conversion (YUV --> RGB)
>> 4. Display Image
>>
>> [...]
>>

-- 
Michael Conrad
IntelliTree Solutions llc.
513-552-6362
[EMAIL PROTECTED]
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