[FFmpeg-devel] [PATCH] Fix printf usage in vhook
Fri Sep 5 09:11:39 CEST 2008
On date Friday 2008-09-05 09:14:41 +0800, JonY encoded:
> Stefano Sabatini wrote:
>> On date Thursday 2008-09-04 12:54:48 +0800, JonY encoded:
>>> Stefano Sabatini wrote:
>>>> On date Wednesday 2008-09-03 19:04:27 +0800, JonY encoded:
>>>>> Patch fixes some undefined references to "please_use_av_log". Do change
>>>>> the AV_LOG levels if inappropriate.
>>>>> Any ideas fix fprintfs writing to files?
>>>>>> vhook/fish.c:369: fprintf(f, "P6 %d %d 255\n", width, height);
>>>>>> vhook/ppm.c:287: fprintf( out, "P6\n%d %d\n255\n", width, height );
>>>> You have to redefine the av_log() behaviour, setting the av_log callback
>>> Do you have any suggestions where the callback should be pointed to?
>> Now that I think at it that lines of code print to some file, but
>> they're not used for logging purpose so I think it makes no sense to
>> use av_log, it would make more sense to #undef fprintf in the files.
>>>> As you may know VHOOK is harshly *deprecated*, nonetheless since we
>>>> don't know how much time libavfilter will stay in the limbo, maybe it
>>>> would still make sense to apply this.
>>> Thanks, I know its depreciated, but I don't know why the errors appeared
>>> now, just trying to correct it.
>> Look at libavutil/internal.h which is included in libavutil/common.h,
>> printing functions shouldn't be used in a library.
> I meant to say that vhook hasn't changed in a while, but why did the
> errors appear only recently? Anyway, I found the cause after checking up
> FFMPEG_FRAMEHOOK_H was changed to AVFORMAT_FRAMEHOOK_H recently in
> libavformat/framehook.h but the ifdefs in libavutil/internal.h, hasn't
> changed to reflect that.
> Patch attached.
> Index: libavutil/internal.h
> --- libavutil/internal.h (revision 15214)
> +++ libavutil/internal.h (working copy)
> @@ -242,7 +242,7 @@
> #define strcat strcat_is_forbidden_due_to_security_issues_use_av_strlcat
> #undef exit
> #define exit exit_is_forbidden
> -#if !(defined(LIBAVFORMAT_BUILD) || defined(FFMPEG_FRAMEHOOK_H))
> +#if !(defined(LIBAVFORMAT_BUILD) || defined(AVFORMAT_FRAMEHOOK_H))
> #undef printf
> #define printf please_use_av_log
> #undef fprintf
That looks like an hack to quickly fix it, the correct solution seems
to me to *not use* f?printf but av_log as in your previous patch (and
#undef it when it is necessary to write to file), then maybe we can
remove that ifdeffery.
FFmpeg = Free and Fiendish MultiPurpose Erotic Geisha
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