Yes, the main audio track comes through, re-encoded to a codec the MP4 container plays, for example AAC in MP4 and MOV or Opus in WebM. Most conversions keep only that one track (the one with the most channels), so alternate languages and commentary are dropped. MP4 to MOV, and AVI, WMV, MPEG, FLV or VOB to MKV with the default settings, keep every audio track.
It depends on what happens to the video. MKV to MP4 or MOV with the default settings copies the video stream unchanged, so the size stays close to the source. Most other pairs re-encode it: a high-bitrate AV1 usually comes out smaller, while an already heavily compressed one can grow. Smaller File under Quality gives the smallest output, and H.265 in the Codec setting (MP4, MOV and MKV) is usually smaller than H.264 at similar quality but plays on fewer devices.
There is no fixed time: it depends on the length, the resolution and the target format. Conversions run on our servers' CPUs with software encoders; there is no GPU acceleration. MKV to MP4 or MOV with the default settings copies the video stream and is the quickest. A re-encode to H.264 takes longer, and WebM (VP9) is the slowest target, several times slower than H.264 in our tests.
The converter has no resolution cap of its own; the limit is the upload size allowed on your plan, and the resolution stays as it is unless you choose 1080p, 720p or 480p. There is no HDR processing or tone mapping. When the video stream is copied (MKV to MP4 or MOV with the default settings), HDR10 passes through untouched. A re-encode drops the HDR10 mastering metadata, and with a Quality, Resolution or Frame Rate setting some pairs also reduce the video to 8-bit colour, so an HDR AV1 can look washed out.
Not in the same step. Use /trim-video/ or /video-cutter/ to clip the AV1 first, or /rotate-video/ to turn it, then run the AV1 to MP4 conversion. Trimming first is faster than re-encoding the whole AV1 just to drop unused footage.
