[FFmpeg-devel] [PATCH] avformat/fifo: Check for keyframe video type before stop dropping

[Arthur Grillo]

The current behavior when using restart_with_keyframe is that it will
recover if it also encounters any audio packet, as they are flagged as a
keyframe.

The expectation is that packets are dropped until the next _video_
keyframe.

Fix that by checking the packet stream codec type, only letting it
recover when it is a video one.

Fixes ticket: #11467

Signed-off-by: Arthur Grillo <arthurgrillo at riseup.net>
---
Cc: lingjiujianke at gmail.com
---
 libavformat/fifo.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/libavformat/fifo.c b/libavformat/fifo.c
index 23e4149ad606b201aade77e28057afe8e5fe2b71..1ebfa1f38f3affec2d81b5a2bb9d69190a5aa63f 100644
--- a/libavformat/fifo.c
+++ b/libavformat/fifo.c
@@ -185,14 +185,21 @@ static int fifo_thread_write_packet(FifoThreadContext *ctx, AVPacket *pkt)
     AVRational src_tb, dst_tb;
     int ret, s_idx;
     int64_t orig_pts, orig_dts, orig_duration;
+    enum AVMediaType stream_codec_type = avf->streams[pkt->stream_index]->codecpar->codec_type;
 
     if (fifo->timeshift && pkt->dts != AV_NOPTS_VALUE)
         atomic_fetch_sub_explicit(&fifo->queue_duration, next_duration(avf, pkt, &ctx->last_received_dts), memory_order_relaxed);
 
     if (ctx->drop_until_keyframe) {
         if (pkt->flags & AV_PKT_FLAG_KEY) {
-            ctx->drop_until_keyframe = 0;
-            av_log(avf, AV_LOG_VERBOSE, "Keyframe received, recovering...\n");
+            if (stream_codec_type == AVMEDIA_TYPE_VIDEO) {
+                ctx->drop_until_keyframe = 0;
+                av_log(avf, AV_LOG_VERBOSE, "Video keyframe received, recovering...\n");
+            } else {
+                av_log(avf, AV_LOG_VERBOSE, "Dropping non-video keyframe\n");
+                av_packet_unref(pkt);
+                return 0;
+            }
         } else {
             av_log(avf, AV_LOG_VERBOSE, "Dropping non-keyframe packet\n");
             av_packet_unref(pkt);

---
base-commit: 3165fe5ecf4917d9f7d7f27d4fa3af31bc604515
change-id: 20250312-video-only-kf-recover-18816009f240

Best regards,
-- 
Arthur Grillo <arthurgrillo at riseup.net>