Hector Martin

so, I could walk you through how to use libavfilter to convert to YUV, libavcodec to encode using x264 (or just depend on x264 directly), and libavformat to write to disk in the container of your choice or you could write out to a pipe, and point ffmpeg CLI at that pipe as input

so there's a Rust crate that wraps x264 and it seems easy to use, how'd I go at wrapping that into some proper container?

note that you _can_ throw RGB directly at x264, but it's not gonna produce something that much of anything actually supports playing, so you'll probably want to make sure you convert to YUV first

you'll want to init your muxer with avformat_alloc_output_context2, then make your stream with avformat_new_stream, configure all the basics in stream->codecpar; that includes extradata from x264_encoder_headers if writing a format with a global header (MP4, MKV; not MPEGTS)

then you avformat_write_header; make AVPackets, pass to av_write_frame; finish with av_write_trailer, cleanup with avformat_free_context

... I think I'll just save the raw h264 stream and instruct the user to run ffmpeg on it

rudimentary scaling: SwsContext* ctx = sws_getCachedContext(0, w, h, AV_PIX_FMT_RGB24, w, h, AV_PIX_FMT_YUV420P, SWS_LANCZOS, NULL, NULL, NULL); sws_scale(ctx, inData, inStride, 0, h, outData, outStride);

that'll convert from RGB to YUV at the same resolution; you might want to double the resolution to mitigate subsampling artifacts, and maybe use SWS_POINT for nearest-neighbor instead of lanczos (¯\_(ツ)_/¯)