It’s harder than it seems. If you want to use the encoder as you’re doing, by calling IMFTransform interface directly, you have to convert RGB frames to NV12. If you want good performance, you should do it on GPU. Possible to do with pixel shaders, render 2 frames, full size one into DXGI_FORMAT_R8_UNORM render target … Read more
Since 2016-07-13, it’s possible to encode VP9/webm videos with alpha channel (VP9a). However, the command you use here will create a VP8a video. Assuming you got a copy of ffmpeg compiled after that date, all you need is change the libvpx to libvpx-vp9. You don’t need the yuva420p conversion either (is selected by default).
When you use subprocess, your command must either be a string that looks exactly like what you would type on the command line (and you set shell=True), or a list where each command is an item in the list (and you take the default shell=False). In either case, you have to deal with the variable … Read more
The problem is that electron-builder or electron-packager will bundle your dependency into the asar file. It seems that if the dependency has a binary into node_modules/.bin it is smart enough to not package it. This is the documentation for asar packaging for electron-builder on that topic. It says Node modules, that must be unpacked, will … Read more
The quality of that command’s output is bad for a few reasons: It is encoding using the MPEG-1 codec, which is quite outdated. You are not setting the bitrate, so it is coming up with its own guess, which is probably inadequate. Try something like: ffmpeg -f image2 -i image%d.jpg -vcodec mpeg4 -b 800k video.avi … Read more
I solved! ffmpeg -i input.mp4 -lavfi ‘[0:v]scale=ih*16/9:-1,boxblur=luma_radius=min(h\,w)/20:luma_power=1:chroma_radius=min(cw\,ch)/20:chroma_power=1[bg];[bg][0:v]overlay=(W-w)/2:(H-h)/2,crop=h=iw*9/16’ -vb 800K output.webm Input: https://www.youtube.com/watch?v=17uHCHfgs60 Output: http://www.youtube.com/watch?v=CgZsDLfzrTs
With Recent version, ffmpeg -i in.mp3 -i test.png -map 0:0 -map 1:0 -c copy -id3v2_version 3 -metadata:s:v title=”Album cover” -metadata:s:v comment=”Cover (front)” out.mp3 Use -map to associate input stream to the output Use -c copy to directly demux/remux The -id3v2_version 3 is what is missing in your command line. Note that that wil write an … Read more
FFmpeg removed libfaac support in 2016 because the other AAC encoders are better. Use a different encoder. Native FFmpeg AAC Encoder (-c:a aac) Use the native, built-in FFmpeg AAC encoder: ffmpeg -i input.wav -c:a aac output.m4a Included by default in all ffmpeg versions. Has many features, fairly good quality, supports the most channel layouts and … Read more
The wav container just adds a simple header to the raw PCM data. The header includes the format, sample rate, and number of channels. Since the raw PCM data does not include this information, you will need to specify it on the command line. Options are specified before the file they apply to, so options … Read more
Of course you could code up some C/C++ and link to -lav*, basically creating a simplified version of ffmpeg just for extracting frames, and maybe even do it as a php extension (also I wouldn’t run it as the same user, let alone in the same process). But the result is very unlikely to be … Read more