[FFmpeg-devel] [PATCH 2/4 v2] ffmpeg: ensure a keyframe was not seen before skipping packets

[James Almer]

A keyframe could be buffered in the bsf and not be output until more packets
had been fed to it.

Signed-off-by: James Almer <jamrial at gmail.com>
---
Changed the check from pkt to !eof, since a packet is always provided.

 fftools/ffmpeg.c | 4 +++-
 fftools/ffmpeg.h | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index 44043ef203..2b61c0d5aa 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -890,6 +890,8 @@ static void output_packet(OutputFile *of, AVPacket *pkt,
 
     /* apply the output bitstream filters */
     if (ost->bsf_ctx) {
+        if (!eof && pkt->flags & AV_PKT_FLAG_KEY)
+            ost->seen_kf = 1;
         ret = av_bsf_send_packet(ost->bsf_ctx, eof ? NULL : pkt);
         if (ret < 0)
             goto finish;
@@ -2035,7 +2037,7 @@ static void do_streamcopy(InputStream *ist, OutputStream *ost, const AVPacket *p
     }
 
     if ((!ost->frame_number && !(pkt->flags & AV_PKT_FLAG_KEY)) &&
-        !ost->copy_initial_nonkeyframes)
+        !ost->copy_initial_nonkeyframes && !ost->seen_kf)
         return;
 
     if (!ost->frame_number && !ost->copy_prior_start) {
diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index 82f3db6b6d..6a19dc9c7c 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -534,6 +534,7 @@ typedef struct OutputStream {
     int inputs_done;
 
     const char *attachment_filename;
+    int seen_kf;
     int copy_initial_nonkeyframes;
     int copy_prior_start;
     char *disposition;
-- 
2.35.1