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

[Michael Niedermayer]

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

Frequently ignored answer#1 FFmpeg bugs should be sent to our bugtracker. User
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And questions about how to use libav* should be sent to the libav-user ML.
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