[FFmpeg-devel] [PATCH] dts parser fails to parse DTS-HD Master streams due to changing frame size

[Benjamin Larsson]

elupus wrote:
> On Tue, 10 Jun 2008 22:57:44 +0200, elupus wrote:
>
>   
>> Hi, 
>>
>> Currently the dts parser in lavc fails to parse dts-hd master streams due
>> to them having changing framesizes. 
>>
>> For some reason the parser requries that the framesize's are equal. Can't
>> really see why that should be required. So this patch removes that
>> requirement.
>>
>> Joakim
>>     
>
> This is getting silly..
> ------------------------------------------------------------------------
>
> Index: libavcodec/dca_parser.c
> ===================================================================
> --- libavcodec/dca_parser.c	(revision 13738)
> +++ libavcodec/dca_parser.c	(working copy)
> @@ -32,8 +32,6 @@
>  typedef struct DCAParseContext {
>      ParseContext pc;
>      uint32_t lastmarker;
> -    int size;
> -    int framesize;
>  } DCAParseContext;
>  
>  #define IS_MARKER(state, i, buf, buf_size) \
> @@ -73,13 +71,10 @@
>      }
>      if (start_found) {
>          for (; i < buf_size; i++) {
> -            pc1->size++;
>              state = (state << 8) | buf[i];
> -            if (state == pc1->lastmarker && IS_MARKER(state, i, buf, buf_size) && (!pc1->framesize || pc1->framesize == pc1->size)) {
> +            if (state == pc1->lastmarker && IS_MARKER(state, i, buf, buf_size)) {
>                  pc->frame_start_found = 0;
>                  pc->state = -1;
> -                pc1->framesize = pc1->size;
> -                pc1->size = 0;
>                  return i - 3;
>              }
>          }
>   

This might break some core streams. It might find markers at random and 
send incomplete frames to the decoder. I guess the spec we have is 
incomplete with regard to newer streams. I'll try to locate a problem 
stream and see if this change breaks it.

MvH
Benjamin Larsson