[FFmpeg-devel] [PATCH 2/2] avcodec/v4l2_context: Finish draining if V4L2_BUF_FLAG_LAST is set

Andriy Gelman andriy.gelman at gmail.com
Thu Apr 30 00:29:42 EEST 2020


From: Andriy Gelman <andriy.gelman at gmail.com>

V4L2 api can indicate that flushing of the capture buffers is completed
by setting the V4L2_BUF_FLAG_LAST flag.
Use guards because the flag was only defined in Linux v4.2.

Reference:
linux/Documentation/media/uapi/v4l/dev-decoder.rst

    "The client must continue to handle both queues independently,
     similarly to normal decode operation. This includes:
     ...
     - queuing and dequeuing CAPTURE buffers, until a buffer marked with
       the V4L2_BUF_FLAG_LAST flag is dequeued"

Signed-off-by: Andriy Gelman <andriy.gelman at gmail.com>
---
 libavcodec/v4l2_context.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/v4l2_context.c b/libavcodec/v4l2_context.c
index f0ecc18ebd..da802405e4 100644
--- a/libavcodec/v4l2_context.c
+++ b/libavcodec/v4l2_context.c
@@ -400,6 +400,10 @@ dequeue:
                 ctx->done = 1;
                 return NULL;
             }
+#ifdef V4L2_BUF_FLAG_LAST
+            if (buf.flags & V4L2_BUF_FLAG_LAST)
+                ctx->done = 1;
+#endif
         }
 
         avbuf = &ctx->buffers[buf.index];
-- 
2.25.1



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