[FFmpeg-cvslog] avfilter/vf_colorcorrect: add median analyze mode
Paul B Mahol
git at videolan.org
Fri Aug 27 11:05:09 EEST 2021
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Wed Aug 25 19:12:47 2021 +0200| [dc34bf45c5bf1518e9c1dae8f705e113f939da9e] | committer: Paul B Mahol
avfilter/vf_colorcorrect: add median analyze mode
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=dc34bf45c5bf1518e9c1dae8f705e113f939da9e
---
doc/filters.texi | 10 ++-
libavfilter/vf_colorcorrect.c | 139 +++++++++++++++++++++++++++++++++++++++---
2 files changed, 141 insertions(+), 8 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 47ceeb18c6..269f2920d1 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -8235,7 +8235,15 @@ Default value is 1.
@item analyze
If set to anything other than @code{manual} it will analyze every frame and use derived
-parameters for filtering output frame. Can be @code{manual} or @code{average} or @code{minmax}.
+parameters for filtering output frame.
+
+Possible values are:
+ at table @samp
+ at item manual
+ at item average
+ at item minmax
+ at item median
+ at end table
Default value is @code{manual}.
@end table
diff --git a/libavfilter/vf_colorcorrect.c b/libavfilter/vf_colorcorrect.c
index 1a8341ebd3..2570bb105c 100644
--- a/libavfilter/vf_colorcorrect.c
+++ b/libavfilter/vf_colorcorrect.c
@@ -31,6 +31,7 @@ typedef enum AnalyzeMode {
MANUAL,
AVERAGE,
MINMAX,
+ MEDIAN,
NB_ANALYZE
} AnalyzeMode;
@@ -49,6 +50,9 @@ typedef struct ColorCorrectContext {
int planeheight[4];
int planewidth[4];
+ unsigned *uhistogram;
+ unsigned *vhistogram;
+
float (*analyzeret)[4];
int (*do_analyze)(AVFilterContext *s, void *arg,
@@ -191,6 +195,114 @@ static int minmax_slice16(AVFilterContext *ctx, void *arg, int jobnr, int nb_job
return 0;
}
+static int median_8(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ ColorCorrectContext *s = ctx->priv;
+ AVFrame *frame = arg;
+ const float imax = s->imax;
+ const int width = s->planewidth[1];
+ const int height = s->planeheight[1];
+ const int ulinesize = frame->linesize[1];
+ const int vlinesize = frame->linesize[2];
+ const uint8_t *uptr = (const uint8_t *)frame->data[1];
+ const uint8_t *vptr = (const uint8_t *)frame->data[2];
+ unsigned *uhistogram = s->uhistogram;
+ unsigned *vhistogram = s->vhistogram;
+ const int half_size = width * height / 2;
+ int umedian = s->max, vmedian = s->max;
+ unsigned ucnt = 0, vcnt = 0;
+
+ memset(uhistogram, 0, sizeof(*uhistogram) * (s->max + 1));
+ memset(vhistogram, 0, sizeof(*vhistogram) * (s->max + 1));
+
+ for (int y = 0; y < height; y++) {
+ for (int x = 0; x < width; x++) {
+ uhistogram[uptr[x]]++;
+ vhistogram[vptr[x]]++;
+ }
+
+ uptr += ulinesize;
+ vptr += vlinesize;
+ }
+
+ for (int i = 0; i < s->max + 1; i++) {
+ ucnt += uhistogram[i];
+ if (ucnt >= half_size) {
+ umedian = i;
+ break;
+ }
+ }
+
+ for (int i = 0; i < s->max + 1; i++) {
+ vcnt += vhistogram[i];
+ if (vcnt >= half_size) {
+ vmedian = i;
+ break;
+ }
+ }
+
+ s->analyzeret[0][0] = imax * umedian - 0.5f;
+ s->analyzeret[0][1] = imax * vmedian - 0.5f;
+ s->analyzeret[0][2] = imax * umedian - 0.5f;
+ s->analyzeret[0][3] = imax * vmedian - 0.5f;
+
+ return 0;
+}
+
+static int median_16(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ ColorCorrectContext *s = ctx->priv;
+ AVFrame *frame = arg;
+ const float imax = s->imax;
+ const int width = s->planewidth[1];
+ const int height = s->planeheight[1];
+ const int ulinesize = frame->linesize[1] / 2;
+ const int vlinesize = frame->linesize[2] / 2;
+ const uint16_t *uptr = (const uint16_t *)frame->data[1];
+ const uint16_t *vptr = (const uint16_t *)frame->data[2];
+ unsigned *uhistogram = s->uhistogram;
+ unsigned *vhistogram = s->vhistogram;
+ const int half_size = width * height / 2;
+ int umedian = s->max, vmedian = s->max;
+ unsigned ucnt = 0, vcnt = 0;
+
+ memset(uhistogram, 0, sizeof(*uhistogram) * (s->max + 1));
+ memset(vhistogram, 0, sizeof(*vhistogram) * (s->max + 1));
+
+ for (int y = 0; y < height; y++) {
+ for (int x = 0; x < width; x++) {
+ uhistogram[uptr[x]]++;
+ vhistogram[vptr[x]]++;
+ }
+
+ uptr += ulinesize;
+ vptr += vlinesize;
+ }
+
+ for (int i = 0; i < s->max + 1; i++) {
+ ucnt += uhistogram[i];
+ if (ucnt >= half_size) {
+ umedian = i;
+ break;
+ }
+ }
+
+ for (int i = 0; i < s->max + 1; i++) {
+ vcnt += vhistogram[i];
+ if (vcnt >= half_size) {
+ vmedian = i;
+ break;
+ }
+ }
+
+ s->analyzeret[0][0] = imax * umedian - 0.5f;
+ s->analyzeret[0][1] = imax * vmedian - 0.5f;
+ s->analyzeret[0][2] = imax * umedian - 0.5f;
+ s->analyzeret[0][3] = imax * vmedian - 0.5f;
+
+ return 0;
+}
+
#define PROCESS() \
float y = yptr[x * chroma_w] * imax; \
float u = uptr[x] * imax - .5f; \
@@ -285,24 +397,25 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
AVFilterContext *ctx = inlink->dst;
ColorCorrectContext *s = ctx->priv;
- const int nb_threads = FFMIN(s->planeheight[1], ff_filter_get_nb_threads(ctx));
+ const int nb_threads = s->analyze == MEDIAN ? 1 : FFMIN(s->planeheight[1], ff_filter_get_nb_threads(ctx));
if (s->analyze) {
+ const int nb_athreads = s->analyze == MEDIAN ? 1 : nb_threads;
float bl = 0.f, rl = 0.f, bh = 0.f, rh = 0.f;
- ff_filter_execute(ctx, s->do_analyze, frame, NULL, nb_threads);
+ ff_filter_execute(ctx, s->do_analyze, frame, NULL, nb_athreads);
- for (int i = 0; i < nb_threads; i++) {
+ for (int i = 0; i < nb_athreads; i++) {
bl += s->analyzeret[i][0];
rl += s->analyzeret[i][1];
bh += s->analyzeret[i][2];
rh += s->analyzeret[i][3];
}
- bl /= nb_threads;
- rl /= nb_threads;
- bh /= nb_threads;
- rh /= nb_threads;
+ bl /= nb_athreads;
+ rl /= nb_athreads;
+ bh /= nb_athreads;
+ rh /= nb_athreads;
s->bl = -bl;
s->rl = -rl;
@@ -347,6 +460,14 @@ static av_cold int config_input(AVFilterLink *inlink)
s->imax = 1.f / s->max;
s->do_slice = s->depth <= 8 ? colorcorrect_slice8 : colorcorrect_slice16;
+ s->uhistogram = av_calloc(s->max == 255 ? 256 : 65536, sizeof(*s->uhistogram));
+ if (!s->uhistogram)
+ return AVERROR(ENOMEM);
+
+ s->vhistogram = av_calloc(s->max == 255 ? 256 : 65536, sizeof(*s->vhistogram));
+ if (!s->vhistogram)
+ return AVERROR(ENOMEM);
+
s->analyzeret = av_calloc(inlink->h, sizeof(*s->analyzeret));
if (!s->analyzeret)
return AVERROR(ENOMEM);
@@ -360,6 +481,9 @@ static av_cold int config_input(AVFilterLink *inlink)
case MINMAX:
s->do_analyze = s->depth <= 8 ? minmax_slice8 : minmax_slice16;
break;
+ case MEDIAN:
+ s->do_analyze = s->depth <= 8 ? median_8 : median_16;
+ break;
default:
return AVERROR_BUG;
}
@@ -411,6 +535,7 @@ static const AVOption colorcorrect_options[] = {
{ "manual", "manually set options", 0, AV_OPT_TYPE_CONST, {.i64=MANUAL}, 0, 0, VF, "analyze" },
{ "average", "use average pixels", 0, AV_OPT_TYPE_CONST, {.i64=AVERAGE}, 0, 0, VF, "analyze" },
{ "minmax", "use minmax pixels", 0, AV_OPT_TYPE_CONST, {.i64=MINMAX}, 0, 0, VF, "analyze" },
+ { "median", "use median pixels", 0, AV_OPT_TYPE_CONST, {.i64=MEDIAN}, 0, 0, VF, "analyze" },
{ NULL }
};
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