diff --git a/doc/filters.texi b/doc/filters.texi index 1d70f4d934..b9b539acee 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -28713,10 +28713,10 @@ it'll always be captured. @item framerate Maximum framerate at which the desktop will be captured - the interval between successive frames will not be smaller than the inverse of the framerate. When -the desktop is not being updated often enough, the filter will duplicate -a previous frame. Note that there is no background buffering going on, so when -the filter is not polled often enough then the actual inter-frame interval may -be significantly larger. +@var{dup_frames} is true (the default) and the desktop is not being updated +often enough, the filter will duplicate a previous frame. Note that there is no +background buffering going on, so when the filter is not polled often enough +then the actual inter-frame interval may be significantly larger. Defaults to 30 FPS. @@ -28749,6 +28749,13 @@ Passes all supported output formats to DDA and returns what DDA decides to use. Filter initialization will fail if 10 bit format is requested but unavailable. @end table +@item dup_frames +When this option is set to true (the default), the filter will duplicate frames +when the desktop has not been updated in order to maintain approximately +constant target framerate. When this option is set to false, the filter will +wait for the desktop to be updated (inter-frame intervals may vary significantly +in this case). + @end table @subsection Examples diff --git a/libavfilter/vsrc_ddagrab.c b/libavfilter/vsrc_ddagrab.c index 9c59faf53e..51e928d785 100644 --- a/libavfilter/vsrc_ddagrab.c +++ b/libavfilter/vsrc_ddagrab.c @@ -101,6 +101,7 @@ typedef struct DdagrabContext { int out_fmt; int allow_fallback; int force_fmt; + int dup_frames; } DdagrabContext; #define OFFSET(x) offsetof(DdagrabContext, x) @@ -124,6 +125,8 @@ static const AVOption ddagrab_options[] = { OFFSET(allow_fallback), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS }, { "force_fmt", "exclude BGRA from format list (experimental, discouraged by Microsoft)", OFFSET(force_fmt), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS }, + { "dup_frames", "duplicate frames to maintain framerate", + OFFSET(dup_frames), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS }, { NULL } }; @@ -1067,7 +1070,9 @@ static int ddagrab_request_frame(AVFilterLink *outlink) now -= dda->first_pts; if (!dda->probed_texture) { - ret = next_frame_internal(avctx, &cur_texture, 0); + do { + ret = next_frame_internal(avctx, &cur_texture, 0); + } while (ret == AVERROR(EAGAIN) && !dda->dup_frames); } else { cur_texture = dda->probed_texture; dda->probed_texture = NULL;