Video Decoder timing issue

[thomas.jourdan1]

Hi

I am still investigating the video decoder behavior and I face another issue. As described here, I wrote a sample app to exercise video decoding. This app is single threaded, and handles both output and capture plane in the same loop. The main loop basically does:

while (!end of file)
    read a frame from file
    queue encoded frame to output plane
    try to dequeue already processed encoded frame from output plane
    queue a buffer to capture plane
    try to dequeue already decoded frame from capture plane
    wait a certain amount of time

The app works fine, when the wait delay is 0. However, as soon as I introduce a delay (in milliseconds), I see errors like :
reference in DPB was never decoded
or
NVDEC_COMMON: NvDecGetSurfPinHandle : Surface not registered

I’ve attached the sample app to the topic. For example:

# Run with no delay
# No decoding errors
decode_error -i bbb_sunflower_1080p_30fps_normal.m2ts --delay 0

# Introduce a 100ms delay in the decoding loop
# will produce reference in DPB was never decoded and NVDEC_COMMON: NvDecGetSurfPinHandle : Surface not registered

decode_error -i bbb_sunflower_1080p_30fps_normal.m2ts --delay 100

What could explain this behavior ? Does the decoder expect the buffers to be queued / unqueued at a minimun rate ? Does the decoder recycle some buffers after a certain amount of time ?

Of course a real application will not introduce such delay but in case of input stream coming from the network, where I can not guarantee the packets will arrive at fixed rate, the delay simulates network stalls. And according to other topics, I saw a lot of person having troubles with RTSP streams and reference in DPB was never decoded, including me. In my case this is not a connection issue, no packets are lost.

Regards
Thomas

decode_error.tar.gz (7.5 KB)

[DaneLLL]

Hi,
In the sample it looks like output plane and capture plane are queued/dequeued in the same thread. In the reference samples, we have output plane in one thread and capture plane in the other. Please check if you can try this way and see if it works.