Expands the parser to also accept the separator '-' in addition to '+', and take the negative sign into consideration.
Signed-off-by: Moritz Barsnick <barsn...@gmx.net> --- doc/filters.texi | 2 +- libavfilter/af_pan.c | 8 +++++--- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/doc/filters.texi b/doc/filters.texi index 4b2f7bf..64934f7 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -3001,7 +3001,7 @@ 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 3037864..f395c71 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; @@ -178,11 +178,13 @@ 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; -- 2.7.4 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel