[FFmpeg-devel] [PATCH] fftools/ffmpeg: Fix EOF pts for libavfilter in send_filter_eof()

[Li-Heng Chen]

When input is video bitstream (e.g. *.264) with framerate set by -r, ist->pts could be a nonsense value.

In libavfilter/vf_fps, the pts value of EOF from above is compared to pts derived from inlink. The wrong EOF pts may trigger a bug, where ffmpeg keeps writting the last video frame to the output. This bug can be easily reproduced by the ffmpeg cmd below (h264 bitstreams in fate-suite can reproduce this issue):

ffmpeg -r num_in/den_in -i bitstream -vf fps=num_out/den_out -f rawvideo out.yuv

Example: ffmpeg -r 24/1 -i fate-suite/h264/bbc2.sample.h264 -vf fps=24/1 -f rawvideo out.yuv
Signed-off-by: Li-Heng Chen <lihengc at netflix.com>
---
fftools/ffmpeg.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index 0e1477299d..e9a986c95b 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -2383,6 +2383,9 @@ static int send_filter_eof(InputStream *ist)
    int64_t pts = av_rescale_q_rnd(ist->pts, AV_TIME_BASE_Q, ist->st->time_base,
                                   AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);

+    if(ist->framerate.num)
+        pts = ist->cfr_next_pts;
+
    for (i = 0; i < ist->nb_filters; i++) {
        ret = ifilter_send_eof(ist->filters[i], pts);
        if (ret < 0)
-- 
2.32.1 (Apple Git-133)