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| author | Hendrik Leppkes <h.leppkes@gmail.com> | 2012-09-14 12:45:34 -0400 |
|---|---|---|
| committer | Derek Buitenhuis <derek.buitenhuis@gmail.com> | 2012-09-15 19:49:34 -0400 |
| commit | e3a1eb9edf65edda301f3a727f11e0224b9f5ae2 (patch) | |
| tree | 8e44a00c97ec69e428d20160e877e6fa75f53b52 | |
| parent | d512e74dec756787417b72776eece32466552724 (diff) | |
| download | ffmpeg-e3a1eb9edf65edda301f3a727f11e0224b9f5ae2.tar.gz | |
af_pan: Fix sscanf formats to work with buggy sscanf implementations
Some implementations of sscanf do not handle a space before a trailing %n
properly.
As an example, MSVC's does this for the second insatnce in this patch, for
an input of "0x3:c0=c1:c1=c0":
1) Match the final "c0" or "c1".
2) Realize it's at the end of the string.
3) Check for %n.
4) There is no %n, but a space instead.
5) Leave 'len' unitilialized.
So, move it out of the sscanf format strings, and call skip_spaces instead.
This bug does not affect skip_spaces since %n is the first and only formatting
string.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
| -rw-r--r-- | libavfilter/af_pan.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/libavfilter/af_pan.c b/libavfilter/af_pan.c index 753522b76e..80a912e3ae 100644 --- a/libavfilter/af_pan.c +++ b/libavfilter/af_pan.c @@ -60,7 +60,7 @@ static int parse_channel_name(char **arg, int *rchannel, int *rnamed) int64_t layout, layout0; /* try to parse a channel name, e.g. "FL" */ - if (sscanf(*arg, " %7[A-Z] %n", buf, &len)) { + if (sscanf(*arg, "%7[A-Z]%n", buf, &len)) { layout0 = layout = av_get_channel_layout(buf); /* channel_id <- first set bit in layout */ for (i = 32; i > 0; i >>= 1) { @@ -78,7 +78,7 @@ static int parse_channel_name(char **arg, int *rchannel, int *rnamed) return 0; } /* try to parse a channel number, e.g. "c2" */ - if (sscanf(*arg, " c%d %n", &channel_id, &len) && + if (sscanf(*arg, "c%d%n", &channel_id, &len) && channel_id >= 0 && channel_id < MAX_CHANNELS) { *rchannel = channel_id; *rnamed = 0; @@ -143,6 +143,7 @@ static av_cold int init(AVFilterContext *ctx, const char *args0) "Invalid out channel name \"%.8s\"\n", arg0); return AVERROR(EINVAL); } + skip_spaces(&arg); if (*arg == '=') { arg++; } else if (*arg == '<') { @@ -156,7 +157,7 @@ static av_cold int init(AVFilterContext *ctx, const char *args0) /* gains */ while (1) { gain = 1; - if (sscanf(arg, " %lf %n* %n", &gain, &len, &len)) + if (sscanf(arg, "%lf%n *%n", &gain, &len, &len)) arg += len; if (parse_channel_name(&arg, &in_ch_id, &named)){ av_log(ctx, AV_LOG_ERROR, @@ -170,6 +171,7 @@ static av_cold int init(AVFilterContext *ctx, const char *args0) return AVERROR(EINVAL); } pan->gain[out_ch_id][in_ch_id] = gain; + skip_spaces(&arg); if (!*arg) break; if (*arg != '+') { @@ -177,7 +179,6 @@ static av_cold int init(AVFilterContext *ctx, const char *args0) return AVERROR(EINVAL); } arg++; - skip_spaces(&arg); } } pan->need_renumber = !!nb_in_channels[1]; |