On Sat, Apr 9, 2022 at 8:31 PM morgan holly via ffmpeg-user < [email protected]> wrote:
> >> > >> > >> > On Sat, Apr 9, 2022 at 5:22 PM morgan holly via ffmpeg-user < > [email protected] <mailto:[email protected]>> wrote: > >> > this is part question and part warning. When I run the cmd below > FFMPEG automatically knocks my 24bit source audio down to 8bits(!). I was > able to change that by adding 'aformat=sample_fmts=s32' into the > filterchain for the anullsrc inputs. > >> > > >> > The warning is: make sure you check your output quality if you use > lavfi slugs with your audio. 24->8bits, yikes. > >> > > >> > The question is: Can I specify the format of the nullsource when > using lavfi. Seems dangerous that it defaults to fmt:u8. Am I doing > something wrong? > >> > > >> > You are not setting aformat right after anullsrc filter. > >> > > >> > >> Thanks for the response. I googled it out and ended up with this: > >> > >> ffmpeg -y -f lavfi -t 1.724 -i > anullsrc=channel_layout=mono:sample_rate=48000,aformat=s32 -ss 120 -t > 30.327979 -i /tmp/2ch.mov -f lavfi -t 1.724 -i > anullsrc=channel_layout=mono:sample_rate=48000,aformat=s32 -filter_complex > "[0:a:0][1:a:0][2:a:0]concat=n=3:v=0:a=1[sf1_out]" -map [sf1_out] > /tmp/noisetest.wav > >> > >> It works, but it does seem odd that the default bit depth of nullsrc > would be 8. > > > > That is because your source is not connected with rest of filters, so > guessing best format never can happen. > > I don’t understand, but would like to. I have three sources here: mov and > 2 lavfi, everything is connected in concat. > -f lavfi is disconnected from rest of -filter_complex filters. _______________________________________________ > ffmpeg-user mailing list > [email protected] > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
