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| author | Andriy Gelman <andriy.gelman@gmail.com> | 2020-04-30 10:58:37 -0400 |
|---|---|---|
| committer | Andriy Gelman <andriy.gelman@gmail.com> | 2020-04-30 11:00:15 -0400 |
| commit | 2a9d62356152d4ef079416101664f26d2562c681 (patch) | |
| tree | d504f231044117a802a4b4718342e54c87685ae6 | |
| parent | c810a9502cebe32e1dd08ee3d0d17053dde44aa9 (diff) | |
| download | ffmpeg-2a9d62356152d4ef079416101664f26d2562c681.tar.gz | |
avcodec/v4l2_context: Log warning when all capture buffers are in userspace
v4l2_m2m uses device memory mapped buffers to store dequeued
frames/packets (reference counted by AVBufferRef). When the reference
count drops to zero, the buffer ownership is returned back to the
device, so that they can re-filled with frames/packets.
There are some cases when all the capture buffers are in userspace
(i.e. due to internal buffering in ffmpeg). On the s5p-mfc this causes
an infinite wait when polling to dequeue the buffers, which can be
prevented by increasing the total number of buffers. This commit adds a
warning when all the capture buffers are dequeued.
Reviewed-by: Ming Qian <ming.qian@nxp.com>
Signed-off-by: Andriy Gelman <andriy.gelman@gmail.com>
| -rw-r--r-- | libavcodec/v4l2_context.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/libavcodec/v4l2_context.c b/libavcodec/v4l2_context.c index 6c2db5c849..f70e151ec8 100644 --- a/libavcodec/v4l2_context.c +++ b/libavcodec/v4l2_context.c @@ -291,6 +291,18 @@ static V4L2Buffer* v4l2_dequeue_v4l2buf(V4L2Context *ctx, int timeout) }; int i, ret; + if (!V4L2_TYPE_IS_OUTPUT(ctx->type) && ctx->buffers) { + for (i = 0; i < ctx->num_buffers; i++) { + if (ctx->buffers[i].status == V4L2BUF_IN_DRIVER) + break; + } + if (i == ctx->num_buffers) + av_log(logger(ctx), AV_LOG_WARNING, "All capture buffers returned to " + "userspace. Increase num_capture_buffers " + "to prevent device deadlock or dropped " + "packets/frames.\n"); + } + /* if we are draining and there are no more capture buffers queued in the driver we are done */ if (!V4L2_TYPE_IS_OUTPUT(ctx->type) && ctx_to_m2mctx(ctx)->draining) { for (i = 0; i < ctx->num_buffers; i++) { |