[FFmpeg-devel] 回复: [EXT] Re: [PATCH] avcodec/v4l2_buffers: don't prevent enqueue capture buffer to driver

[Andriy Gelman]

On Thu, 09. Apr 02:14, Ming Qian wrote:
> Did you try increasing the -num_capture_buffers option? It may solve your problem.
> 1. We can't increase the num_capture_buffers indefinitely.
> 2. There is a ring buffer in driver, so the number of frames who is stored in the ring buffer may be a large value, This depends on the speed of the input and output. So it's likely that when output port is done, there are a large count of frames who have not been decoded,  if the capture port prevent qbuf to driver, there will no frame buffer to store the decoded frame.
> 
> There is currently a check that sets ctx->done=1 when all the capture buffers are dequeued (v4l2_context.c:300), and this patch would prevent it (although it's not needed if an eos event is received).

> Yes, but I think it's not appropriate to judge whether the capture port is done by checking all the capture buffers are dequeued.
> 

I tend to agree with you. Even if eos event is not setup/supported, we should
be able to set ctx->done=1 via the EPIPE error.  

But let's wait for some more comments. 

-- 
Andriy