[FFmpeg-devel] [PATCH] stop av_find_stream_info per packet dts

[Baptiste Coudurier]

Michael Niedermayer wrote:
> On Sat, Mar 14, 2009 at 08:50:25PM -0700, Baptiste Coudurier wrote:
>> Michael Niedermayer wrote:
>>> On Sat, Mar 14, 2009 at 08:25:25PM -0700, Baptiste Coudurier wrote:
>>>> Hi
>>>>
>>>> It seems stopping av_find_stream_info by packet duration causes a
>>>> problem when a packet with long duration (still image, sub) is very long.
>>>>
>>>> Scenario:
>>>> 1 video stream containing a single image with very long duration
>>>> 1 video stream cfr.
>>>>
>>>> Demuxing will happen in this order since dts are in this order.
>>>>
>>>> av_find_stream_info will stop after the single image, while the next
>>>> packet dts will still be < max analyze duration.
>>>>
>>>> I'd like your opinion on this I don't know if this might have side effects.
>>> i think the idea is good but dts might not start at 0 (cut mpeg-ps/ts being
>>> an example)
>>> also before you write a patch that sums dts differences, this can break
>>> with timestamp discontinuities.
>>> maybe something like using the previous sum of durations for each stream
>>> instead of the latest?
>>>
>> Like this ?
>>
>
> [...]
> 
> no i meant to move the codec_info_duration check before the change that is
> 
> if(codec_info_nb_frames[st->index]>1){
>     if (st->time_base.den > 0 && av_rescale_q(codec_info_duration[st->index], st->time_base, AV_TIME_BASE_Q) >= ic->max_analyze_duration)
>         break;
>     codec_info_duration[st->index] += pkt->duration;
> }
> 
> a possible problem with your suggestion is that it might never reach
> the break if some stream simply doesnt contain any (more) packets
> 

Right, I understand now.

Patch attached.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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