[FFmpeg-devel] [PATCH] increase AVStream pts_buffer size

[Baptiste Coudurier]

Hi Michael,

Michael Niedermayer wrote:
> On Sat, Aug 09, 2008 at 06:28:47PM -0700, Baptiste Coudurier wrote:
>> Hi Michael,
>>
>> Michael Niedermayer wrote:
>>> On Sat, Aug 09, 2008 at 05:34:51PM -0700, Baptiste Coudurier wrote:
>>>> Baptiste Coudurier wrote:
>>>>> M?ns Rullg?rd wrote:
>>>>>> Baptiste Coudurier <baptiste.coudurier at smartjog.com> writes:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> H264 decoder can (now?) set has_b_frames to MAX_DELAYED_PIC_COUNT which
>>>>>>> is 16, need to port this to pts_buffer in AVStream struct.
>>>>>>>
>>>>>>> compute_pkt_files in utils.c:
>>>>>>> int delay = FFMAX(st->codec->has_b_frames, !!st->codec->max_b_frames);
>>>>>>>
>>>>>>> [...]
>>>>>>>
>>>>>>> //calculate dts from pts
>>>>>>> if(pkt->pts != AV_NOPTS_VALUE && pkt->dts == AV_NOPTS_VALUE){
>>>>>>>     st->pts_buffer[0]= pkt->pts;
>>>>>>>     for(i=1; i<delay+1 && st->pts_buffer[i] == AV_NOPTS_VALUE; i++)
>>>>>>>         st->pts_buffer[i]= (i-delay-1) * pkt->duration;
>>>>>>>     for(i=0; i<delay && st->pts_buffer[i] > st->pts_buffer[i+1]; i++)
>>>>>>>         FFSWAP(int64_t, st->pts_buffer[i], st->pts_buffer[i+1]);
>>>>>>>      pkt->dts= st->pts_buffer[0];
>>>>>>> }
>>>>>>>
>>>>>>> Patch attached.
>>>>>>>
>>>>>>> Index: libavformat/avformat.h
>>>>>>> ===================================================================
>>>>>>> --- libavformat/avformat.h	(revision 14513)
>>>>>>> +++ libavformat/avformat.h	(working copy)
>>>>>>> @@ -385,7 +385,7 @@
>>>>>>>  
>>>>>>>      int64_t nb_frames;                 ///< number of frames in this stream if known or 0
>>>>>>>  
>>>>>>> -#define MAX_REORDER_DELAY 4
>>>>>>> +#define MAX_REORDER_DELAY 16
>>>>>>>      int64_t pts_buffer[MAX_REORDER_DELAY+1];
>>>>>>>  
>>>>>>>      char *filename; /**< source filename of the stream */
>>>>>> This breaks ABI, so it needs a version bump.  Others can have an
>>>>>> opinion on how bad that is.
>>>>>>
>>>>> Right, we can avoid going too far in the mean time to avoid breaking
>>>>> ABI, it is not the right solution I believe but it should fix the bug,
>>>>> patch attached.
>>>>>
>>>>>
>>>>>
>>>>> ------------------------------------------------------------------------
>>>>>
>>>>> Index: libavformat/utils.c
>>>>> ===================================================================
>>>>> --- libavformat/utils.c	(revision 14513)
>>>>> +++ libavformat/utils.c	(working copy)
>>>>> @@ -2472,7 +2472,7 @@
>>>>>      //calculate dts from pts
>>>>>      if(pkt->pts != AV_NOPTS_VALUE && pkt->dts == AV_NOPTS_VALUE){
>>>>>          st->pts_buffer[0]= pkt->pts;
>>>>> -        for(i=1; i<delay+1 && st->pts_buffer[i] == AV_NOPTS_VALUE; i++)
>>>>> +        for(i=1; i<delay+1 && i < MAX_REORDER_DELAY+1 && st->pts_buffer[i] == AV_NOPTS_VALUE; i++)
>>>>>              st->pts_buffer[i]= (i-delay-1) * pkt->duration;
>>>>>          for(i=0; i<delay && st->pts_buffer[i] > st->pts_buffer[i+1]; i++)
>>>>>              FFSWAP(int64_t, st->pts_buffer[i], st->pts_buffer[i+1]);
>>>>>
>>>> Any comments ? This fixes a bug :>
>>> too fe hours each day ... :)
>>>
>>> i think there ae 2 issues here.
>>> first is that MAX_REORDER_DELAY is too small, that can be fixed adding a
>>> new pts_buffer at the end of AVStream that is bigger and putting the old
>>> one under #if VERSION<...
>>>
>> Thanks for review, patch attached.
> 
> ok, but i would name the old pts_buffer2 and the new pts_buffer, this should
> make the diff smaller
> 

Oh yeah, good idea, and both hunk can be applied separately.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
Smartjog USA Inc.                                http://www.smartjog.com
Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
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