first post and new forum member here. Thanks for letting me be part of the community.
While being fairly new to video encoding itself, I think I already know a little bit about the background workings.
Here is what I'm trying to solve either through a GUI or CLI:
Converting H.264 to H.265 using NVENC using setting or parameters, which let me set a factor for my target file size based on the original file size.
input: 3GB file H.264 @3Mb/sec -> output settings: H.265 using NVEnc @ Data ratio 0.66 or 66% -> output: 2GB file H.265 @2Mb/sec
I want to run batch conversion of files, which come at different bit rates and different resolutions. I found that H.264 to H.265 at factor 0.66 yields about the same visual quality at a significant reduction in file size.
After crawling the web for a few days, I've only been able to found one front-end GUI that offers exactly that, which is MediaCoder. Unfortunately for batch conversion, there are some limitations in the free version and I can't justify spending $200 to make my life easier.
If anyone knows how to make NVEnc pick a bit rate based on bit rate of the original file using CLI or maybe knows of an alternative to MediaCoder, I'd be very happy about any pointers.
I've been testing various front-ends like StaxRip or MeGUI, etc and while all offer great options to run batches, the automatic ratio calculation seems to be missing from all of them.
Thanks in advance for your time.
+ Reply to Thread
Results 1 to 5 of 5
Personally I don't think it's worth the time and effort. But...
You can use MediaInfo to get the bitrate and save it as an environment variable. Then use ffmpeg to do the encoding at 2/3 that bitrate. This batch file will encode all the mp4 files in a folder to hevc mkv files in a subfolder called new:
md new setlocal enabledelayedexpansion for %%F in ("*.mp4") do ( "G:\Program Files\MediainfoCLI\Mediainfo.exe" --Inform=Video;%%BitRate%% "%%~F" >bitrate.txt set /p bitrate=<"bitrate.txt" del bitrate.txt "G:\Program Files\ffmpeg64\bin\ffmpeg.exe" -y -i "%%~F" -c:v hevc_qsv -preset:v veryfast -b:v !bitrate!*0.66 -c:a copy "new\%%~nF.hevc.mkv" ) endlocal pause
Wow, that is a great solution! Thanks, exactly what I was looking for!
Played around with it and it now does exactly what I need. The only thing that didn;t work was the veryfast preset, as it doesn't seem to exists in NVEnc: Eventually replaced it with fast. The other option would have been hp (high performance).
Again thanks a lot!
Last edited by Greg4rious; 2nd Jul 2020 at 20:43.
The irony is that "2/3" is not even close to being a standard reduction ratio, unless you only work in a narrow range of bitrates and only deal with a narrow type of content.
But it"s your dime.
You can get a list of options specific to the NVENC encoder with "ffmpeg -? encoder=hevc_nvenc". You should check them out too.
Encoder hevc_nvenc [NVIDIA NVENC hevc encoder]: General capabilities: delay hardware Threading capabilities: none Supported pixel formats: yuv420p nv12 p010le yuv444p p016le yuv444p16le bgr0 rgb0 cuda d3d11 hevc_nvenc AVOptions: -preset <int> E..V..... Set the encoding preset (from 0 to 11) (default medium) default E..V..... slow E..V..... hq 2 passes medium E..V..... hq 1 pass fast E..V..... hp 1 pass hp E..V..... hq E..V..... bd E..V..... ll E..V..... low latency llhq E..V..... low latency hq llhp E..V..... low latency hp lossless E..V..... lossless losslesshp E..V..... lossless hp -profile <int> E..V..... Set the encoding profile (from 0 to 4) (default main) main E..V..... main10 E..V..... rext E..V..... -level <int> E..V..... Set the encoding level restriction (from 0 to 186) (default auto) auto E..V..... 1 E..V..... 1.0 E..V..... 2 E..V..... 2.0 E..V..... 2.1 E..V..... 3 E..V..... 3.0 E..V..... 3.1 E..V..... 4 E..V..... 4.0 E..V..... 4.1 E..V..... 5 E..V..... 5.0 E..V..... 5.1 E..V..... 5.2 E..V..... 6 E..V..... 6.0 E..V..... 6.1 E..V..... 6.2 E..V..... -tier <int> E..V..... Set the encoding tier (from 0 to 1) (default main) main E..V..... high E..V..... -rc <int> E..V..... Override the preset rate-control (from -1 to INT_MAX) (default -1) constqp E..V..... Constant QP mode vbr E..V..... Variable bitrate mode cbr E..V..... Constant bitrate mode vbr_minqp E..V..... Variable bitrate mode with MinQP (deprecated) ll_2pass_quality E..V..... Multi-pass optimized for image quality (deprecated) ll_2pass_size E..V..... Multi-pass optimized for constant frame size (deprecated) vbr_2pass E..V..... Multi-pass variable bitrate mode (deprecated) cbr_ld_hq E..V..... Constant bitrate low delay high quality mode cbr_hq E..V..... Constant bitrate high quality mode vbr_hq E..V..... Variable bitrate high quality mode -rc-lookahead <int> E..V..... Number of frames to look ahead for rate-control (from 0 to INT_MAX) (default 0) -surfaces <int> E..V..... Number of concurrent surfaces (from 0 to 64) (default 0) -cbr <boolean> E..V..... Use cbr encoding mode (default false) -2pass <boolean> E..V..... Use 2pass encoding mode (default auto) -gpu <int> E..V..... Selects which NVENC capable GPU to use. First GPU is 0, second is 1, and so on. (from -2 to INT_MAX) (default any) any E..V..... Pick the first device available list E..V..... List the available devices -delay <int> E..V..... Delay frame output by the given amount of frames (from 0 to INT_MAX) (default INT_MAX) -no-scenecut <boolean> E..V..... When lookahead is enabled, set this to 1 to disable adaptive I-frame insertion at scene cuts (default false) -forced-idr <boolean> E..V..... If forcing keyframes, force them as IDR frames. (default false) -spatial_aq <boolean> E..V..... set to 1 to enable Spatial AQ (default false) -temporal_aq <boolean> E..V..... set to 1 to enable Temporal AQ (default false) -zerolatency <boolean> E..V..... Set 1 to indicate zero latency operation (no reordering delay) (default false) -nonref_p <boolean> E..V..... Set this to 1 to enable automatic insertion of non-reference P-frames (default false) -strict_gop <boolean> E..V..... Set 1 to minimize GOP-to-GOP rate fluctuations (default false) -aq-strength <int> E..V..... When Spatial AQ is enabled, this field is used to specify AQ strength. AQ strength scale is from 1 (low) - 15 (aggressive) (from 1 to 15) (default 8) -cq <float> E..V..... Set target quality level (0 to 51, 0 means automatic) for constant quality mode in VBR rate control (from 0 to 51) (default 0) -aud <boolean> E..V..... Use access unit delimiters (default false) -bluray-compat <boolean> E..V..... Bluray compatibility workarounds (default false) -init_qpP <int> E..V..... Initial QP value for P frame (from -1 to 51) (default -1) -init_qpB <int> E..V..... Initial QP value for B frame (from -1 to 51) (default -1) -init_qpI <int> E..V..... Initial QP value for I frame (from -1 to 51) (default -1) -qp <int> E..V..... Constant quantization parameter rate control method (from -1 to 51) (default -1) -weighted_pred <int> E..V..... Set 1 to enable weighted prediction (from 0 to 1) (default 0) -b_ref_mode <int> E..V..... Use B frames as references (from 0 to 2) (default disabled) disabled E..V..... B frames will not be used for reference each E..V..... Each B frame will be used for reference middle E..V..... Only (number of B frames)/2 will be used for reference
Last edited by jagabo; 3rd Jul 2020 at 07:22.