[FFmpeg-devel] [PATCH 1/2] avfilter/colorize: add speed option

[Yannis Gerlach]

The speed option allows to have a constant (per frame) change of hue. 
This allows for an easy way of creating an color changing effect without 
relying on somewhat complicated expressions.

Signed-off-by: Yannis Gerlach <ffmpeg at ygerlach.de>
---
libavfilter/vf_colorize.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/libavfilter/vf_colorize.c b/libavfilter/vf_colorize.c
index e6c563e3e2..cfcf1a54fb 100644
--- a/libavfilter/vf_colorize.c
+++ b/libavfilter/vf_colorize.c
@@ -29,6 +29,7 @@ typedef struct ColorizeContext {
float saturation;
float lightness;
float mix;
+ float speed;
int depth;
int c[3];
@@ -205,6 +206,13 @@ static int filter_frame(AVFilterLink *inlink, 
AVFrame *frame)
ff_filter_execute(ctx, do_slice, frame, NULL,
FFMIN(s->planeheight[1], ff_filter_get_nb_threads(ctx)));
+ s->hue += s->speed;
+ if (s->hue < 0.f) {
+ s->hue += 360.f;
+ } else if(s->hue > 360.f) {
+ s->hue -= 360.f;
+ }
+
return ff_filter_frame(ctx->outputs[0], frame);
}
@@ -267,6 +275,7 @@ static const AVOption colorize_options[] = {
{ "saturation", "set the saturation", OFFSET(saturation), 
AV_OPT_TYPE_FLOAT, {.dbl=0.5},0, 1, VF },
{ "lightness", "set the lightness", OFFSET(lightness), 
AV_OPT_TYPE_FLOAT, {.dbl=0.5},0, 1, VF },
{ "mix", "set the mix of source lightness", OFFSET(mix), 
AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 1, VF },
+ { "speed", "set the change of hue per frame", OFFSET(speed), 
AV_OPT_TYPE_FLOAT, {.dbl=0}, -180, 180, VF },
{ NULL }
};
-- 2.34.1




Am 01.05.24 um 09:49 schrieb Gyan Doshi:
>
>
> On 2024-05-01 12:18 pm, Yannis Gerlach wrote:
>> The speed option allows to have a constant (per frame) change of hue. 
>> This allows for an easy way of creating an color changing effect 
>> without relying on somewhat complicated expressions.
>>
>> Signed-off-by: Yannis Gerlach <ffmpeg at ygerlach.de>
>> ---
>>  libavfilter/vf_colorize.c | 17 +++++++++++++----
>>  1 file changed, 13 insertions(+), 4 deletions(-)
>>
>> diff --git a/libavfilter/vf_colorize.c b/libavfilter/vf_colorize.c
>> index e6c563e3e2..ad8577c8fd 100644
>> --- a/libavfilter/vf_colorize.c
>> +++ b/libavfilter/vf_colorize.c
>> @@ -29,6 +29,7 @@ typedef struct ColorizeContext {
>>      float saturation;
>>      float lightness;
>>      float mix;
>> +    float speed;
>>       int depth;
>>      int c[3];
>> @@ -205,6 +206,13 @@ static int filter_frame(AVFilterLink *inlink, 
>> AVFrame *frame)
>>      ff_filter_execute(ctx, do_slice, frame, NULL,
>>                        FFMIN(s->planeheight[1], 
>> ff_filter_get_nb_threads(ctx)));
>>  +    s->hue += s->speed;
>> +    if (s->hue < 0.f) {
>> +        s->hue += 360.f;
>> +    } else if(s->hue > 360.f) {
>> +        s->hue -= 360.f;
>> +    }
>> +
>>      return ff_filter_frame(ctx->outputs[0], frame);
>>  }
>>  @@ -263,10 +271,11 @@ static const AVFilterPad colorize_inputs[] = {
>>  #define VF 
>> AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
>>   static const AVOption colorize_options[] = {
>> -    { "hue",        "set the hue", OFFSET(hue), AV_OPT_TYPE_FLOAT, 
>> {.dbl=0},  0, 360, VF },
>> -    { "saturation", "set the saturation", OFFSET(saturation), 
>> AV_OPT_TYPE_FLOAT, {.dbl=0.5},0,   1, VF },
>> -    { "lightness",  "set the lightness", OFFSET(lightness), 
>> AV_OPT_TYPE_FLOAT, {.dbl=0.5},0,   1, VF },
>> -    { "mix",        "set the mix of source lightness", OFFSET(mix), 
>>    AV_OPT_TYPE_FLOAT, {.dbl=1},  0,   1, VF },
>> +    { "hue",        "set the hue", OFFSET(hue), AV_OPT_TYPE_FLOAT, 
>> {.dbl=0},    0, 360, VF },
>> +    { "saturation", "set the saturation", OFFSET(saturation), 
>> AV_OPT_TYPE_FLOAT, {.dbl=0.5},  0,   1, VF },
>> +    { "lightness",  "set the lightness", OFFSET(lightness), 
>> AV_OPT_TYPE_FLOAT, {.dbl=0.5},  0,   1, VF },
>> +    { "mix",        "set the mix of source lightness", OFFSET(mix), 
>>    AV_OPT_TYPE_FLOAT, {.dbl=1},    0,   1, VF },
>
> The cosmetic changes should be in a separate patch.

I have split them now.

>
> Regards,
> Gyan
>
>> +    { "speed",      "set the change of hue per frame", 
>> OFFSET(speed), AV_OPT_TYPE_FLOAT, {.dbl=0}, -180, 180, VF },
>>      { NULL }
>>  };
>>  -- 2.34.1
>>
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