[FFmpeg-devel] [PATCH] lavfi/setpts: set framerate constant when defined

[Stefano Sabatini]

Useful for constant frame-rate video.

TODO: bump micro
---
 doc/filters.texi       |    3 +++
 libavfilter/f_setpts.c |   11 +++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index 0b57eed..677c4fa 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -4194,6 +4194,9 @@ Accept in input an expression evaluated through the eval API, which
 can contain the following constants:
 
 @table @option
+ at item FRAME_RATE
+frame rate, only defined for constant frame-rate video
+
 @item PTS
 the presentation timestamp in input
 
diff --git a/libavfilter/f_setpts.c b/libavfilter/f_setpts.c
index 177d29b..61446c1 100644
--- a/libavfilter/f_setpts.c
+++ b/libavfilter/f_setpts.c
@@ -35,6 +35,7 @@
 #include "video.h"
 
 static const char *const var_names[] = {
+    "FRAME_RATE",  ///< defined only for constant-frame-rate video
     "INTERLACED",  ///< tell if the current frame is interlaced
     "N",           ///< frame number (starting at zero)
     "NB_CONSUMED_SAMPLES", ///< number of samples consumed by the filter (only audio)
@@ -54,6 +55,7 @@ static const char *const var_names[] = {
 };
 
 enum var_name {
+    VAR_FRAME_RATE,
     VAR_INTERLACED,
     VAR_N,
     VAR_NB_CONSUMED_SAMPLES,
@@ -107,8 +109,13 @@ static int config_input(AVFilterLink *inlink)
     if (setpts->type == AVMEDIA_TYPE_AUDIO)
         setpts->var_values[VAR_SAMPLE_RATE] = inlink->sample_rate;
 
-    av_log(inlink->src, AV_LOG_VERBOSE, "TB:%f SAMPLE_RATE:%f\n",
-           setpts->var_values[VAR_TB], setpts->var_values[VAR_SAMPLE_RATE]);
+    setpts->var_values[VAR_FRAME_RATE] = inlink->frame_rate.num && inlink->frame_rate.den ?
+        av_q2d(inlink->frame_rate) : NAN;
+
+    av_log(inlink->src, AV_LOG_VERBOSE, "TB:%f FRAME_RATE:%f SAMPLE_RATE:%f\n",
+           setpts->var_values[VAR_TB],
+           setpts->var_values[VAR_FRAME_RATE],
+           setpts->var_values[VAR_SAMPLE_RATE]);
     return 0;
 }
 
-- 
1.7.5.4