[FFmpeg-devel] [FFmpeg-cvslog] av_format/hlsenc: fix %v handling by format_name function

[Liu Steven]

> 在 2019年6月20日，上午1:37，Michael Niedermayer <michael at niedermayer.cc> 写道：
> 
> On Wed, Jun 19, 2019 at 10:03:51AM +0000, Bodecs Bela wrote:
>> ffmpeg | branch: master | Bodecs Bela <bodecsb at vivanet.hu> | Mon Jun 17 23:05:21 2019 +0200| [09a4853930e7950f423e9161004871afe659ed84] | committer: Steven Liu
>> 
>> av_format/hlsenc: fix %v handling by format_name function
>> 
>> Hi All,
>> 
>> When multiple variant streams are specified by var_stream_map option, %v
>> placeholder in various names ensures that each variant has its unique
>> names. Most of %v handlng is done in format_name function. Currently
>> in this function the result buffer is the same as the
>> input pattern buffer, so you must allocate it before calling format_name
>> function. It also means, that it is silently assumed that the result
>> string will NOT be
>> longer that the pattern string. It is true most of the time, because %v
>> may appear only once in the pattern string and number of variant streams
>> is less than 100 in practical cases. But theoretically it will fail if
>> specified number of variant streams is greater than 100 (i.e. longer
>> than 2 digits).
>> This patch fixes this behaviour by altering format_name function to
>> allocate the
>> result buffer and return it to the caller.
>> 
>> Please, review this patch.
>> 
>> best,
>> 
>> Bela
>>> From 6377ebee8a106a9684d41b270c7d6c8e57cd3e7b Mon Sep 17 00:00:00 2001
>> From: Bela Bodecs <bodecsb at vivanet.hu>
>> Date: Mon, 17 Jun 2019 14:31:36 +0200
>> Subject: [PATCH] av_format/hlsenc: fix %v handling by format_name function
>> 
>> When multiple variant streams are specified by var_stream_map option, %v
>> placeholder in various names ensures that each variant has its unique
>> names. Most of %v handlng is done in format_name function. Currently
>> in this function the result buffer is the same as the input pattern
>> buffer, so you must allocate it before calling format_name function. It
>> also means, that it is silently assumed that the result string will NOT
>> be longer that the pattern string. It is true most of the time, because
>> %v may appear only once in the pattern string and number of variant
>> streams is less than 100 in practical cases. But theoretically it will
>> fail if specified number of variant streams is greater than 100. This
>> patch fixes this behaviour by altering format_name function to allocate
>> the result buffer and return it to the caller.
>> 
>> Signed-off-by: Bela Bodecs <bodecsb at vivanet.hu>
> 
> This broke fate (segfaults) also it produces new compiler warnings which
> probably are pointing to the cause
> 
> libavformat/hlsenc.c: In function ‘hls_init’:
> libavformat/hlsenc.c:2643:9: warning: passing argument 2 of ‘format_name’ makes pointer from integer without a cast [enabled by default]
>         ret = format_name(s->url, i, vs->m3u8_name);
>         ^
> libavformat/hlsenc.c:1764:12: note: expected ‘char **’ but argument is of type ‘int’
> static int format_name(const char *buf, char **s, int index)
>            ^
> libavformat/hlsenc.c:2643:9: warning: passing argument 3 of ‘format_name’ makes integer from pointer without a cast [enabled by default]
>         ret = format_name(s->url, i, vs->m3u8_name);
>         ^
> libavformat/hlsenc.c:1764:12: note: expected ‘int’ but argument is of type ‘char *’
> static int format_name(const char *buf, char **s, int index)
>            ^
> libavformat/hlsenc.c:2712:13: warning: passing argument 2 of ‘format_name’ makes pointer from integer without a cast [enabled by default]
>             ret = format_name(vs->basename, basename_size, i);
>             ^
> libavformat/hlsenc.c:1764:12: note: expected ‘char **’ but argument is of type ‘int’
> static int format_name(const char *buf, char **s, int index)
>            ^
> libavformat/hlsenc.c:2767:25: warning: passing argument 2 of ‘format_name’ makes pointer from integer without a cast [enabled by default]
>                         format_name(vs->fmp4_init_filename, fmp4_init_filename_len, i);
>                         ^
> libavformat/hlsenc.c:1764:12: note: expected ‘char **’ but argument is of type ‘int’
> static int format_name(const char *buf, char **s, int index)
>            ^
> libavformat/hlsenc.c:2832:17: warning: passing argument 2 of ‘format_name’ makes pointer from integer without a cast [enabled by default]
>                 ret = format_name(vs->vtt_m3u8_name, vtt_basename_size, i);
>                 ^
> libavformat/hlsenc.c:1764:12: note: expected ‘char **’ but argument is of type ‘int’
> static int format_name(const char *buf, char **s, int index)
> 
> 
> [...]
> -- 
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> 
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Fixed after merged the second patch named “0003-avformat-hlsenc-enhanced-v-handling-with-variant-nam.patch”


Thanks

Steven