[issue2563] AVI encoder create a file (contains multiple video and audio streams) with uncorrect fourcc tag

[longstone]

New submission from longstone <zhibing....@hotmail.com>:

When I'm tring to mux an AVI file with multiple video 
and audio streams, the AVI encoder created a file 
with uncorrect fourcc tag when the total streams' 

count is more than 10.
According to the AVI spec, each stream is assigned 
with one stream ID. If the new file contains 12 
streams (6 video and 6 audio streams respectively), 
their 

stream ID and chunk tag should be:
0: '00dc'
1: '01dc'
2: '02dc'
3: '03dc'
4: '04dc'
5: '05dc'
6: '06wb'
7: '07wb'
8: '08wb'
9: '09wb'
10: '10wb'
11: '11wb'
The truth is that the file created by the current 
version of avi encoder, has got an uncorrect chunk 
tag for streams with stream ID 10 and 11. The chunk 
tag 

are '0:wb' and '0;wb' respectively. 
This can be fixed by modifying the content of the 
following function:

  // Original source
  static char* avi_stream2fourcc(char* tag, int 
index, enum CodecType type)
  {
    tag[0] = '0';
    tag[1] = '0' + index;
    if (type == CODEC_TYPE_VIDEO) {
        tag[2] = 'd';
        tag[3] = 'c';
    } else {
        tag[2] = 'w';
        tag[3] = 'b';
    }
    tag[4] = '\0';
    return tag;
  }

  // Modified
  // However, this works when the total stream number 
<= 99. 
  // If the count is >= 100, no answer then...
  static char* avi_stream2fourcc(char* tag, int 
index, enum CodecType type)
  {
    tag[0] = '0' + (index/10);
    tag[1] = '0' + (index%10);
    if (type == CODEC_TYPE_VIDEO) {
        tag[2] = 'd';
        tag[3] = 'c';
    } else {
        tag[2] = 'w';
        tag[3] = 'b';
    }
    tag[4] = '\0';
    return tag;
  }

----------
messages: 13518
priority: normal
status: new
substatus: new
title: AVI encoder create a file (contains multiple video and audio streams) 
with uncorrect fourcc tag
type: bug

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FFmpeg issue tracker <iss...@roundup.ffmpeg.org>
<https://roundup.ffmpeg.org/issue2563>
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