Convert file to AV1 using hw accel.

[TheDreadPirate]

OK works... is this now a lossless conversation (video) ?

No.  I don't think there is a lossless mode for AV1.  Least not with QSV.  I believe HEVC and H264 software encoders have a lossless mode, but that creates HUGE files.

For most videos, the parameters you used should cause little or no loss in perceivable quality.  Some videos with a ton of film grain, av1_qsv struggles.

btw: so you mean with -map 0 i get also rif of these messages ?
[aost#0:2/copy @ 0x5615c47f5d80] Non-monotonic DTS; previous: 25563, current: 25556; changing to 25563. This may result in incorrect timestamps in the output file.

-map 0 tells ffmpeg to take all the input streams and send them to the output file.

For the message you are referencing, my understanding is that this message caused by a difference in how the frames in original file was time stamped (DTS = decoding time stamp) vs how the new file is being time stamped.  That message is almost always harmless, in my experience.

BTW: additional question.... using pipe:0 as inputfile and pipe:1 as outputfile its then possible to transcode in tvheadend the tv stream on the fly ?

I have no idea.  Sorry.