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

[Andriy Gelman]

On Sun, 26. Apr 23:50, Andriy Gelman wrote:
> On Thu, 09. Apr 00:27, Andriy Gelman wrote:
> > 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. 
> > 
> 
> In [1] it says that capture buffers should be enqueued back to the device while
> draining.
> 
> I'll apply this patch on Wednesday if no one objects.
> 

Applied.

Thanks,
-- 
Andriy