[FFmpeg-devel] [PATCH V2 1/2] lavf/vc1test: fix vc1test can't probe some RCV file.

[Carl Eugen Hoyos]

2018-10-12 15:41 GMT+02:00, Jun Zhao <mypopydev at gmail.com>:
> case 1:
> use the hexdump -C SMM0005.rcv get:
>                      size              skip (size - 4)
>                       |                        |
>                       V                        V
> 00000000  18 00 00 c5 05 00 00 00  4d f1 0a 11 00 e0 01 00
> 00000010  00 d0 02 00 00 0c 00 00  00 88 13 00 00 c0 65 52
>                          ^
> 			 |
> 		     size + 16
> case 2:
> same the command for SMM0015.rcv get:
>                     size
>                       |
>                       V
> 00000000  19 00 00 c5 04 00 00 00  41 f3 80 01 40 02 00 00
> 00000010  d0 02 00 00 0c 00 00 00  00 00 00 10 00 00 00 00
>                       ^
> 		      |
> 		   size + 16
>
> There are different the RCV file format for VC-1, vc1test
> just handle the case 2 now, this fix will support the case 1.

Both with and without your patch, I get identical output from
FFmpeg's decoder for both SSM0015.rcv and SMM0005.rcv.
What exactly is your patch supposed to change?

$ md5sum SMM0005.rcv
abd0fa5ec90d44f7b4865c6930d65ff2  SMM0005.rcv
$ md5sum SSM0015.rcv
21a0281f83b7f2e99a048b180dd3347f  SSM0015.rcv

The following does not change:

$ ffmpeg -i SMM0005.rcv -f crc -
ffmpeg version N-92147-gf85fa10 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 6.4.0 (GCC)
  configuration: --enable-gpl --enable-gnutls --enable-libxml2
  libavutil      56. 19.101 / 56. 19.101
  libavcodec     58. 32.100 / 58. 32.100
  libavformat    58. 18.104 / 58. 18.104
  libavdevice    58.  4.105 / 58.  4.105
  libavfilter     7. 33.100 /  7. 33.100
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
  libpostproc    55.  2.100 / 55.  2.100
Input #0, vc1test, from 'SMM0005.rcv':
  Duration: 00:00:01.00, bitrate: 7472 kb/s
    Stream #0:0: Video: wmv3 (Main), yuv420p, 720x480, 24 fps, 24 tbr,
24 tbn, 24 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (wmv3 (native) -> rawvideo (native))
Press [q] to stop, [?] for help
Output #0, crc, to 'pipe:':
  Metadata:
    encoder         : Lavf58.18.104
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p,
720x480, q=2-31, 99532 kb/s, 24 fps, 24 tbn, 24 tbc
    Metadata:
      encoder         : Lavc58.32.100 rawvideo
SMM0005.rcv: Input/output error
    Last message repeated 1 times
CRC=0xe3b2671c
frame=   24 fps=0.0 q=-0.0 Lsize=       0kB time=00:00:01.00 bitrate=
 0.1kbits/s speed=14.8x
video:12150kB audio:0kB subtitle:0kB other streams:0kB global
headers:0kB muxing overhead: unknown

What exactly is your patch supposed to improve?

Thank you, Carl Eugen

(05 looks different here.)