[FFmpeg-devel] [PATCH] MJPEG/AVI1 to JPEG/JFIF byte stream format filter

[Nicolas George]

Le quartidi 14 brumaire, an CCXIX, Michael Niedermayer a ?crit?:
> does ISO C gurantee that sizeof() is what we want it to be ?

What the C standard states is mostly this:

       [#3] When applied to an operand that has type char, unsigned
       char, or signed char, (or a qualified version  thereof)  the
       result  is  1.   When  applied  to an operand that has array
       type, the result  is  the  total  number  of  bytes  in  the
       array.75)

       [#6]  EXAMPLE 2 Another  use  of  the  sizeof operator is to
       compute the number of elements in an array:

               sizeof array / sizeof array[0]

Unless I am mistaken, the only thing that could go wrong here would be if
sizeof(uint8_t) was not 1. I can add the relevant division if you want, but
a lot of lav* code assume, implicitly or explicitly that uint8_t is the same
as unsigned char, so I do not think this would do any good.


New version, with fixed spelling of bitstream, and copy-pasted paragraph
about configure --disable-bsf.

By the way, the effects of this bitstream can be tested with the following
file from the sample collection:
http://samples.mplayerhq.hu/V-codecs/MJPEGs/MVI_3774.AVI

$ ./ffmpeg_g -i /tmp/MVI_3774.AVI -vcodec copy -vframes 1 /tmp/mjpeg%d.jpg
$ display /tmp/mjpeg1.jpg 
display: Huffman table 0x00 was not defined `/tmp/mjpeg1.jpg' @ error/jpeg.c/EmitMessage/233.
$ ./ffmpeg_g -i /tmp/MVI_3774.AVI -vcodec copy -vframes 1 -vbsf mjpeg2jpeg -y /tmp/mjpeg%d.jpg
$ display /tmp/mjpeg1.jpg

> besides this this patch looks ok to me
> also if you want write access and agree to our development policy then contact
> diego

I have just re-read the development policy. If I am granted write access to
the repository, I will try, to the best of my ability, to abide to this
policy.

Regards,

-- 
  Nicolas George
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