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| author | Moritz Barsnick <barsnick@gmx.net> | 2016-10-28 14:13:25 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2016-11-24 00:54:52 +0100 |
| commit | 0700d02a697e0a2901abc6422edfe72a246bae01 (patch) | |
| tree | 7a45073731bd2d0af1d8603e38365dc0b29071ad | |
| parent | 584eea5bf3e40e2dbab986f8e9e8f01c8a4426d2 (diff) | |
| download | ffmpeg-0700d02a697e0a2901abc6422edfe72a246bae01.tar.gz | |
lavfi/pan: allow negative gain parameters also for other inputs than the first named
Expands the parser to also accept the separator '-' in addition to
'+', and take the negative sign into consideration.
The optional sign for the first factor in the expression is already
covered by parsing for an integer.
Signed-off-by: Moritz Barsnick <barsnick@gmx.net>
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | doc/filters.texi | 2 | ||||
| -rw-r--r-- | libavfilter/af_pan.c | 10 |
2 files changed, 8 insertions, 4 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index b15f78a9a0..b3899b2693 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -3026,7 +3026,7 @@ output channel layout or number of channels @item outdef output channel specification, of the form: -"@var{out_name}=[@var{gain}*]@var{in_name}[+[@var{gain}*]@var{in_name}...]" +"@var{out_name}=[@var{gain}*]@var{in_name}[(+-)[@var{gain}*]@var{in_name}...]" @item out_name output channel to define, either a channel name (FL, FR, etc.) or a channel diff --git a/libavfilter/af_pan.c b/libavfilter/af_pan.c index fbd79a5a42..94f15876f5 100644 --- a/libavfilter/af_pan.c +++ b/libavfilter/af_pan.c @@ -102,7 +102,7 @@ static av_cold int init(AVFilterContext *ctx) { PanContext *const pan = ctx->priv; char *arg, *arg0, *tokenizer, *args = av_strdup(pan->args); - int out_ch_id, in_ch_id, len, named, ret; + int out_ch_id, in_ch_id, len, named, ret, sign = 1; int nb_in_channels[2] = { 0, 0 }; // number of unnamed and named input channels double gain; @@ -178,14 +178,18 @@ static av_cold int init(AVFilterContext *ctx) ret = AVERROR(EINVAL); goto fail; } - pan->gain[out_ch_id][in_ch_id] = gain; + pan->gain[out_ch_id][in_ch_id] = sign * gain; skip_spaces(&arg); if (!*arg) break; - if (*arg != '+') { + if (*arg == '-') { + sign = -1; + } else if (*arg != '+') { av_log(ctx, AV_LOG_ERROR, "Syntax error near \"%.8s\"\n", arg); ret = AVERROR(EINVAL); goto fail; + } else { + sign = 1; } arg++; } |