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

[Baptiste Coudurier]

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 :>

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