[FFmpeg-devel] [PATCH v1] avfilter/src_movie: Fix the loop function of dynamic logo

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

The following command will attempt to create the input and overlay test sequence for you.
./ffmpeg -f lavfi  -i color=white:duration=100:r=25:size=1280x720  input.mkv
./ffmpeg -f lavfi -i "testsrc=duration=5:size=320x240:rate=25" overlay.mkv

Please try with below command and compare the final output.
./ffmpeg -y -filter_complex "movie=./input.mkv,setpts=PTS-STARTPTS[main];movie=./overlay.mkv:loop=5,setpts=PTS-STARTPTS[overlay];[main][overlay]overlay=10:10:
 enable='between(t,0,25)" test.mkv

 Without the patch applied, the overlay will repeat the last frame in overlay.mkv after the first loop.

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 libavfilter/src_movie.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavfilter/src_movie.c b/libavfilter/src_movie.c
index 79423a8..2327046 100644
--- a/libavfilter/src_movie.c
+++ b/libavfilter/src_movie.c
@@ -68,6 +68,8 @@ typedef struct MovieContext {
     int loop_count;
     int64_t discontinuity_threshold;
     int64_t ts_offset;
+    int64_t last_pts;
+    int64_t last_loop_pts;
 
     AVFormatContext *format_ctx;
     int eof;
@@ -455,6 +457,7 @@ static int rewind_file(AVFilterContext *ctx)
         movie->st[i].done = 0;
     }
     movie->eof = 0;
+    movie->last_loop_pts = movie->last_pts;
     return 0;
 }
 
@@ -565,6 +568,8 @@ static int movie_push_frame(AVFilterContext *ctx, unsigned out_id)
     if (frame->pts != AV_NOPTS_VALUE) {
         if (movie->ts_offset)
             frame->pts += av_rescale_q_rnd(movie->ts_offset, AV_TIME_BASE_Q, outlink->time_base, AV_ROUND_UP);
+        if (movie->last_loop_pts)
+            frame->pts += movie->last_loop_pts;
         if (st->discontinuity_threshold) {
             if (st->last_pts != AV_NOPTS_VALUE) {
                 int64_t diff = frame->pts - st->last_pts;
@@ -575,6 +580,7 @@ static int movie_push_frame(AVFilterContext *ctx, unsigned out_id)
                 }
             }
         }
+        movie->last_pts =
         st->last_pts = frame->pts;
     }
     ff_dlog(ctx, "movie_push_frame(): file:'%s' %s\n", movie->file_name,
-- 
2.9.5