[FFmpeg-devel] [PATCH] WAV file length (writing to stdout)

Cyril B. cbay
Fri Oct 19 10:33:31 CEST 2007

Michel Bardiaux wrote:
>> To reproduce the tests:
>>   * ffmpeg -i input.mp3 -f wav > output.wav
> Surely not. *Never* re-type the command line, always use copy/paste.

I'm afraid I fail to understand what you mean. What I did was to create an
output.wav file (once) with the bare SVN version (without my patch).
The .wav had 0 as file length. I made sure that output.wav was readable by
most apps (just to be sure).

Then I applied my patch, recompiled ffmpeg and created output.wav with the
same command as before. With my patch applied, it had 36 as a file length.
Then I checked again that this output.wav was readable by the same apps.

What do you mean with 'never re-type the command line'? That specific
command (to create the output.wav) was run exactly twice, using my shell
history the second time, so I did not retype it.

> Have you run 'make test'? Maybe some test results changed due to the
> patch.

make test results are quite cryptic to me, as it already returns errors with
the SVN version (without my patch). Such as:

tests/data/b-libav-yuv420p.yuv: could not find codec parameters
[asf @ 0x83f7654]asf_read_pts failed
[nut @ 0x83f7654]read_timestamp failed.

I also have 'Regression test succeeded.' 4 times.

So what I did was to redirect stdout and stderr to a file, and diffed the
results (of a 'make test') with and without my patch. This is what I got:

> pass:0 changed:7
< pass:0 changed:12
> pass:0 changed:10
gcc -L"/tmp/ffmpeg"/libavformat -L"/tmp/ffmpeg"/libavcodec -L"/tmp/ffmpeg"/libavutil -rdynamic
-export-dynamic -Wl,--warn-common -Wl,--as-needed -Wl,-rpath-link,"/tmp/ffmpeg"/libavcodec
-Wl,-rpath-link,"/tmp/ffmpeg"/libavformat -Wl,-rpath-link,"/tmp/ffmpeg"/libavutil -g
-fomit-frame-pointer -g -Wdeclaration-after-statement -Wall -Wno-switch -Wdisabled-optimization
-Wpointer-arith -Wredundant-decls -Wno-pointer-sign -O3 -I"/tmp/ffmpeg" -I"/tmp/ffmpeg"
-I"/tmp/ffmpeg"/libavutil -I"/tmp/ffmpeg"/libavcodec -I"/tmp/ffmpeg"/libavformat
-DHAVE_AV_CONFIG_H -DHAVE_AV_CONFIG_H -o tests/seek_test
tests/seek_test.c -lavformat -lavcodec -lavutil -lz -lm  -ldl -ldl

Seems OK to me, but I might be wrong.

Cyril B.

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