[FFmpeg-cvslog] lavfi/thumbnail: support flushing.
Clément Bœsch
git at videolan.org
Thu Mar 14 00:16:31 CET 2013
ffmpeg | branch: master | Clément Bœsch <ubitux at gmail.com> | Wed Mar 13 23:59:25 2013 +0100| [a95a38793c75fa8e424f91f1adf1be6ced69f953] | committer: Clément Bœsch
lavfi/thumbnail: support flushing.
This makes possible the raise of one picture if the input has less than
the number of frames to analyze.
Fixes Ticket1992.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a95a38793c75fa8e424f91f1adf1be6ced69f953
---
libavfilter/version.h | 2 +-
libavfilter/vf_thumbnail.c | 99 ++++++++++++++++++++++++++++----------------
2 files changed, 64 insertions(+), 37 deletions(-)
diff --git a/libavfilter/version.h b/libavfilter/version.h
index 8a49673..bcfb12a 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -30,7 +30,7 @@
#define LIBAVFILTER_VERSION_MAJOR 3
#define LIBAVFILTER_VERSION_MINOR 45
-#define LIBAVFILTER_VERSION_MICRO 102
+#define LIBAVFILTER_VERSION_MICRO 103
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
diff --git a/libavfilter/vf_thumbnail.c b/libavfilter/vf_thumbnail.c
index d214253..46ab834 100644
--- a/libavfilter/vf_thumbnail.c
+++ b/libavfilter/vf_thumbnail.c
@@ -41,6 +41,7 @@ typedef struct {
int n; ///< current frame
int n_frames; ///< number of frames for analysis
struct thumb_frame *frames; ///< the n_frames frames
+ AVRational tb; ///< copy of the input timebase to ease access
} ThumbContext;
static av_cold int init(AVFilterContext *ctx, const char *args)
@@ -86,14 +87,52 @@ static double frame_sum_square_err(const int *hist, const double *median)
return sum_sq_err;
}
-static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+static AVFrame *get_best_frame(AVFilterContext *ctx)
{
+ AVFrame *picref;
+ ThumbContext *thumb = ctx->priv;
int i, j, best_frame_idx = 0;
+ int nb_frames = thumb->n;
double avg_hist[HIST_SIZE] = {0}, sq_err, min_sq_err = -1;
+
+ // average histogram of the N frames
+ for (j = 0; j < FF_ARRAY_ELEMS(avg_hist); j++) {
+ for (i = 0; i < nb_frames; i++)
+ avg_hist[j] += (double)thumb->frames[i].histogram[j];
+ avg_hist[j] /= nb_frames;
+ }
+
+ // find the frame closer to the average using the sum of squared errors
+ for (i = 0; i < nb_frames; i++) {
+ sq_err = frame_sum_square_err(thumb->frames[i].histogram, avg_hist);
+ if (i == 0 || sq_err < min_sq_err)
+ best_frame_idx = i, min_sq_err = sq_err;
+ }
+
+ // free and reset everything (except the best frame buffer)
+ for (i = 0; i < nb_frames; i++) {
+ memset(thumb->frames[i].histogram, 0, sizeof(thumb->frames[i].histogram));
+ if (i != best_frame_idx)
+ av_frame_unref(thumb->frames[i].buf);
+ }
+ thumb->n = 0;
+
+ // raise the chosen one
+ picref = thumb->frames[best_frame_idx].buf;
+ av_log(ctx, AV_LOG_INFO, "frame id #%d (pts_time=%f) selected "
+ "from a set of %d images\n", best_frame_idx,
+ picref->pts * av_q2d(thumb->tb), nb_frames);
+ thumb->frames[best_frame_idx].buf = NULL;
+
+ return picref;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+ int i, j;
AVFilterContext *ctx = inlink->dst;
ThumbContext *thumb = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
- AVFrame *picref;
int *hist = thumb->frames[thumb->n].histogram;
const uint8_t *p = frame->data[0];
@@ -111,40 +150,11 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
}
// no selection until the buffer of N frames is filled up
- if (thumb->n < thumb->n_frames - 1) {
- thumb->n++;
+ thumb->n++;
+ if (thumb->n < thumb->n_frames)
return 0;
- }
-
- // average histogram of the N frames
- for (j = 0; j < FF_ARRAY_ELEMS(avg_hist); j++) {
- for (i = 0; i < thumb->n_frames; i++)
- avg_hist[j] += (double)thumb->frames[i].histogram[j];
- avg_hist[j] /= thumb->n_frames;
- }
- // find the frame closer to the average using the sum of squared errors
- for (i = 0; i < thumb->n_frames; i++) {
- sq_err = frame_sum_square_err(thumb->frames[i].histogram, avg_hist);
- if (i == 0 || sq_err < min_sq_err)
- best_frame_idx = i, min_sq_err = sq_err;
- }
-
- // free and reset everything (except the best frame buffer)
- for (i = 0; i < thumb->n_frames; i++) {
- memset(thumb->frames[i].histogram, 0, sizeof(thumb->frames[i].histogram));
- if (i == best_frame_idx)
- continue;
- av_frame_unref(thumb->frames[i].buf);
- }
- thumb->n = 0;
-
- // raise the chosen one
- picref = thumb->frames[best_frame_idx].buf;
- av_log(ctx, AV_LOG_INFO, "frame id #%d (pts_time=%f) selected\n",
- best_frame_idx, picref->pts * av_q2d(inlink->time_base));
- thumb->frames[best_frame_idx].buf = NULL;
- return ff_filter_frame(outlink, picref);
+ return ff_filter_frame(outlink, get_best_frame(ctx));
}
static av_cold void uninit(AVFilterContext *ctx)
@@ -158,18 +168,34 @@ static av_cold void uninit(AVFilterContext *ctx)
static int request_frame(AVFilterLink *link)
{
- ThumbContext *thumb = link->src->priv;
+ AVFilterContext *ctx = link->src;
+ ThumbContext *thumb = ctx->priv;
/* loop until a frame thumbnail is available (when a frame is queued,
* thumb->n is reset to zero) */
do {
- int ret = ff_request_frame(link->src->inputs[0]);
+ int ret = ff_request_frame(ctx->inputs[0]);
+ if (ret == AVERROR_EOF && thumb->n) {
+ ret = ff_filter_frame(link, get_best_frame(ctx));
+ if (ret < 0)
+ return ret;
+ ret = AVERROR_EOF;
+ }
if (ret < 0)
return ret;
} while (thumb->n);
return 0;
}
+static int config_props(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ ThumbContext *thumb = ctx->priv;
+
+ thumb->tb = inlink->time_base;
+ return 0;
+}
+
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat pix_fmts[] = {
@@ -184,6 +210,7 @@ static const AVFilterPad thumbnail_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_props,
.get_video_buffer = ff_null_get_video_buffer,
.filter_frame = filter_frame,
},
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