[FFmpeg-user] When using h264_cuvid, memory allocation differs between different nvidia GPUs

[Panagiotis Malakoudis]

I am using h264_cuvid in some systems. GTX10xx cards have the power to
decode many full hd streams concurrently.
I have found that memory allocated in the GPU differs between GTX 1050 Ti
and GTX 1070 Ti. With the same command, same settings, ffmpeg allocates
only 87MB in GTX 1050 Ti while it allocates 153MB in GTX 1070 Ti. There is
an exact 66MB difference which is critical in my application if it can be
avoided. Is there any reason why this happens and can it be avoided?

Example command:
ffmpeg -c:v h264_cuvid -surfaces 8 -f mpegts -i
https://samples.ffmpeg.org/V-codecs/h264/HD-h264.ts -vcodec libx264 -preset
veryfast -crf 23 -c:a copy -f mpegts transcoded.ts
In GTX 1050 Ti, nvidia-smi output:
+-----------------------------------------------------------------------------+
| Processes:                                                       GPU
Memory |
|  GPU       PID   Type   Process name                             Usage
  |
|=============================================================================|
|    0     28243      C   ffmpeg
87MiB |
+-----------------------------------------------------------------------------+
In GTX 1070 Ti, nvidia-smi output:
+-----------------------------------------------------------------------------+
| Processes:                                                       GPU
Memory |
|  GPU       PID   Type   Process name                             Usage
  |
|=============================================================================|
|    0     10291      C   ffmpeg
 153MiB |
+-----------------------------------------------------------------------------+