[FFmpeg-devel,2/2] avfilter/vf_mix: add scale option

Submitted by Paul B Mahol on April 24, 2018, 12:53 p.m.

Details

Message ID 20180424125329.21212-2-onemda@gmail.com
State New
Headers show

Commit Message

Paul B Mahol April 24, 2018, 12:53 p.m.
Signed-off-by: Paul B Mahol <onemda@gmail.com>
---
 doc/filters.texi     | 10 ++++++++++
 libavfilter/vf_mix.c |  9 ++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

Comments

Gyan April 24, 2018, 1:15 p.m.
On 4/24/2018 6:23 PM, Paul B Mahol wrote:
>   
> +@item scale
> +Specify scale, if it is set it will be multiplied with sum
> +of weigths multiplied with pixel values to give final destination
> +pixel value. By default it is auto scaled to sum of weights.

s/Specify scale, if it is set/If set

s/weigths/weights

"it will be multiplied" & "it is auto scaled" --> what is 'it'?

Range?
Paul B Mahol April 24, 2018, 1:28 p.m.
On 4/24/18, Gyan Doshi <gyandoshi@gmail.com> wrote:
>
>
> On 4/24/2018 6:23 PM, Paul B Mahol wrote:
>>
>> +@item scale
>> +Specify scale, if it is set it will be multiplied with sum
>> +of weigths multiplied with pixel values to give final destination
>> +pixel value. By default it is auto scaled to sum of weights.
>
> s/Specify scale, if it is set/If set
>
> s/weigths/weights
>
> "it will be multiplied" & "it is auto scaled" --> what is 'it'?
>
> Range?

Unlimited.

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diff --git a/doc/filters.texi b/doc/filters.texi
index 23d6063ef4..db686689ea 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -11154,6 +11154,11 @@  The number of inputs. If unspecified, it defaults to 2.
 Specify weight of each input video stream as sequence.
 Each weight is separated by space.
 
+@item scale
+Specify scale, if it is set it will be multiplied with sum
+of weigths multiplied with pixel values to give final destination
+pixel value. By default it is auto scaled to sum of weights.
+
 @item duration
 Specify how end of stream is determined.
 @table @samp
@@ -15574,6 +15579,11 @@  The number of successive frames to mix. If unspecified, it defaults to 3.
 @item weights
 Specify weight of each input video frame.
 Each weight is separated by space.
+
+@item scale
+Specify scale, if it is set it will be multiplied with sum
+of weigths multiplied with pixel values to give final destination
+pixel value. By default it is auto scaled to sum of weights.
 @end table
 
 @section tonemap
diff --git a/libavfilter/vf_mix.c b/libavfilter/vf_mix.c
index 3690b03cf8..8932bd53d7 100644
--- a/libavfilter/vf_mix.c
+++ b/libavfilter/vf_mix.c
@@ -37,6 +37,7 @@  typedef struct MixContext {
     int nb_inputs;
     int duration;
     float *weights;
+    float scale;
     float wfactor;
 
     int tmix;
@@ -109,7 +110,11 @@  static av_cold int init(AVFilterContext *ctx)
         sscanf(arg, "%f", &s->weights[i]);
         s->wfactor += s->weights[i];
     }
-    s->wfactor = 1 / s->wfactor;
+    if (s->scale == 0) {
+        s->wfactor = 1 / s->wfactor;
+    } else {
+        s->wfactor = s->scale;
+    }
 
     return 0;
 }
@@ -275,6 +280,7 @@  static int activate(AVFilterContext *ctx)
 static const AVOption mix_options[] = {
     { "inputs", "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64=2}, 2, INT_MAX, .flags = FLAGS },
     { "weights", "set weight for each input", OFFSET(weights_str), AV_OPT_TYPE_STRING, {.str="1 1"}, 0, 0, .flags = FLAGS },
+    { "scale", "set scale", OFFSET(scale), AV_OPT_TYPE_FLOAT, {.dbl=0}, 0, INT16_MAX, .flags = FLAGS },
     { "duration", "how to determine end of stream", OFFSET(duration), AV_OPT_TYPE_INT, {.i64=0}, 0, 2, .flags = FLAGS, "duration" },
         { "longest",  "Duration of longest input",  0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "duration" },
         { "shortest", "Duration of shortest input", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "duration" },
@@ -336,6 +342,7 @@  static int tmix_filter_frame(AVFilterLink *inlink, AVFrame *in)
 static const AVOption tmix_options[] = {
     { "frames", "set number of successive frames to mix", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64=3}, 2, 128, .flags = FLAGS },
     { "weights", "set weight for each frame", OFFSET(weights_str), AV_OPT_TYPE_STRING, {.str="1 1 1"}, 0, 0, .flags = FLAGS },
+    { "scale", "set scale", OFFSET(scale), AV_OPT_TYPE_FLOAT, {.dbl=0}, 0, INT16_MAX, .flags = FLAGS },
     { NULL },
 };