6 ms·

Honestly, the first step in this is getting the ffmpeg av1 library to a good usable place. It's currently so slow as to be near unviable. I'd happily switch whe

by donatj 6y ago

Honestly, the first step in this is getting the ffmpeg av1 library to a good usable place. It's currently so slow as to be near unviable. I'd happily switch when it becomes a usable option.

zionic 6y ago
Isn't that largely dependent on hardware acceleration from CPU manufacturers? Or is ffmpeg always software encoding?
- oefrha 6y ago
  FFmpeg isn’t “always software encoding”, that statement doesn’t make much sense since FFmpeg/libavcodec is more of an interface and you can add support for any external encoder/decoder, hardware accelerated or not. However, FFmpeg’s builtin encoders and the most popular external encoders including x264 and x265 are all software encoders. There are hardware accelerated encoders from GPU vendors, e.g. the nvenc encoder for H.264 and H.265 is available for use on Nvidia GPUs if your FFmpeg is compiled against CUDA SDK. It’s a lot faster than x264 and x265 on comparable settings but results are usually a bit worse. You were probably thinking about hardware decoding though.
  - donatj 6y ago
    I'm curious why hardware encoding is generally worse? All my experiments with it (h264/h265) have lead to significantly lower quality output to the point that I've avoided it for any final outputs, but I always assumed I was doing something wrong.
    - oefrha 6y ago
      I’ve written various applications on top of FFmpeg but never looked into encoder technicalities, so I don’t know if and why GPU encoding has fundamental limitations. I heard nvenc has vastly improved on RTX cards; I’m still rocking an old GPU so can’t verify that, but presumably that means there’s no fundamental weakness and GPU encoding is just playing catch up?
    - tomku 6y ago
      Hardware encoding cares about consistent real-time output above all else, with power usage as the runner-up. It can focus on that because software encoders are just flat-out better for use cases involving quality - they have access to more flexible/accurate math, they don't necessarily have a real-time/low-latency constraint, they can be updated when new encoding tricks are discovered, they can be massively more complex without ballooning the cost of a device, etc. They're complementary options rather than competing. Each does something well, and it sounds like you want the thing that software encoding does.
- sudosysgen 6y ago
  ffmpeg supports CPU, CPU-Accelerated and GPU-accelerated encoding and decoding.
_Gyan_ 6y ago
There is no ffmpeg av1 library i.e. no native decoders or encoders. ffmpeg has wrappers for libaom and dav1d/rav1e. 3rd party scripts also add wrappers for svt-av1.
zanny 6y ago
Is there any indication that rav1e is so inefficient as to have substantive double digit percentage speedup left to be realized? Because even if you cut encode times in half, they already take hours per minute of video on a quad core. AV1 is unlikely to ever be practical for "muggle" encode use, at least in this decade. It will only be worth committing that much compute workload to making a smaller file if the recipients will number in at least what, millions? I'd be really curious what a hardware realtime AV1 encoder would even look like. How much silicon would that take? That kind of chip would have be be colossal even if it sacrifices huge amounts of efficiency to spit out frames at reasonable time (in the same way hardware hevc and vp9 encoders kind of suck).
- ClumsyPilot 6y ago
  HEVC encoder on 20 series nvidia cards is actually really good
  - fomine3 6y ago
    Ice Lake's also great

by donatj 6y ago

Honestly, the first step in this is getting the ffmpeg av1 library to a good usable place. It's currently so slow as to be near unviable. I'd happily switch when it becomes a usable option.

zionic 6y ago

Isn't that largely dependent on hardware acceleration from CPU manufacturers? Or is ffmpeg always software encoding?

oefrha 6y ago
FFmpeg isn’t “always software encoding”, that statement doesn’t make much sense since FFmpeg/libavcodec is more of an interface and you can add support for any external encoder/decoder, hardware accelerated or not. However, FFmpeg’s builtin encoders and the most popular external encoders including x264 and x265 are all software encoders. There are hardware accelerated encoders from GPU vendors, e.g. the nvenc encoder for H.264 and H.265 is available for use on Nvidia GPUs if your FFmpeg is compiled against CUDA SDK. It’s a lot faster than x264 and x265 on comparable settings but results are usually a bit worse. You were probably thinking about hardware decoding though.
- donatj 6y ago
  I'm curious why hardware encoding is generally worse? All my experiments with it (h264/h265) have lead to significantly lower quality output to the point that I've avoided it for any final outputs, but I always assumed I was doing something wrong.
  - oefrha 6y ago
    I’ve written various applications on top of FFmpeg but never looked into encoder technicalities, so I don’t know if and why GPU encoding has fundamental limitations. I heard nvenc has vastly improved on RTX cards; I’m still rocking an old GPU so can’t verify that, but presumably that means there’s no fundamental weakness and GPU encoding is just playing catch up?
  - tomku 6y ago
    Hardware encoding cares about consistent real-time output above all else, with power usage as the runner-up. It can focus on that because software encoders are just flat-out better for use cases involving quality - they have access to more flexible/accurate math, they don't necessarily have a real-time/low-latency constraint, they can be updated when new encoding tricks are discovered, they can be massively more complex without ballooning the cost of a device, etc. They're complementary options rather than competing. Each does something well, and it sounds like you want the thing that software encoding does.
sudosysgen 6y ago
ffmpeg supports CPU, CPU-Accelerated and GPU-accelerated encoding and decoding.

_Gyan_ 6y ago

There is no ffmpeg av1 library i.e. no native decoders or encoders. ffmpeg has wrappers for libaom and dav1d/rav1e. 3rd party scripts also add wrappers for svt-av1.

zanny 6y ago

Is there any indication that rav1e is so inefficient as to have substantive double digit percentage speedup left to be realized? Because even if you cut encode times in half, they already take hours per minute of video on a quad core. AV1 is unlikely to ever be practical for "muggle" encode use, at least in this decade. It will only be worth committing that much compute workload to making a smaller file if the recipients will number in at least what, millions? I'd be really curious what a hardware realtime AV1 encoder would even look like. How much silicon would that take? That kind of chip would have be be colossal even if it sacrifices huge amounts of efficiency to spit out frames at reasonable time (in the same way hardware hevc and vp9 encoders kind of suck).

ClumsyPilot 6y ago
HEVC encoder on 20 series nvidia cards is actually really good
- fomine3 6y ago
  Ice Lake's also great