File size doubles when using hardware encoder

Help/How To
#1

Hi there!
Shotcut version 20.11.28
Task:
Rendering a straight movie without any effects used. Just clips put together.

  1. If f use no hardware encoding it takes a certain time and results in a certain file size.
  2. If I use hardware encoding (I have got a graphic card with a GPU RX 550) rendering takes less than half the time in comparison to 1. but the file size at least doubles.
    I used the preset “.264 high profile” without any changes.

Is there any way to use the hardware encoding without getting double file size? Maybe when changing the preset parameters? I am not into decoder stuff, it is all Greek to me ;-))
Thank You for Your efforts.
Stay healthy, Me

#2

You should change the name of your thread to “File sizes” because “File lengths” makes it sound like you are talking about the running time.

To answer your question, as far as I know using hardware encoder will result in a file size that is bigger. The only way to get it down while still using the hardware encoder is to lower the video quality. Or if the HEVC codec isn’t an issue for you then you can use that with hardware encoding since HEVC exports smaller file sizes compared to H.264 while still keeping the same quality and see if the file size is more to your liking.

#3

Hi DRM, thank You for you quick answer. I changed the thread’s name.
I will try out the HEVC codec and let You know wht thappened.

#4

Hi again,
I did try out different rendering conditions as You can see:
image

Using .h264 You see the different file sizes wether using GPU or not.
Using HEVC gives exactly the same file sizes. I tried it out twice because I thought I might accidently have used the same conditions, …no!
So the best result concerning file size is .h264 with no GPU although the rendering time is doubled…
Anyway thank You very much for Your help!
Regards, Me

#5

Yes in general Hardware Encoders speed up encoding at the expense of filesize and quality (they produce bigger files at lower quality), which is great for streaming, as they can keep up with the frame-rates needed in real-time, but not for videos.

#6

Tank You Elusien, for the explanation! I’d rather stop experimenting and do as before.