Hi! I am aware of news that AAC encoder got stable status recently. But you could find this interesting. We've got an ffmpeg build from October 2014, and it performs three times faster on AAC encoding than recent 3.0 release. There is no complaints about audio quality on old version, and I can honestly say the audio quality is really satisfiable on old version. The performance is paramount in our particular usecase, so it is silly to deploy a new version which performs so noticeably worse. Still deploying new release is needed due to other particular bugfixes.
Obvious things like lowering bitrace, setting "-aac_coder fast" don't help. You can check this yourself with this script (it is also inlined below): https://gist.github.com/andrey-utkin/c60cd4070eb962d58075 On my workstation, the old version finishes the transcoding in 2.5s, the new one in 6.6s. Is there any workaround? Or is the old times speed is buried by correctness and stability? #!/bin/bash set -e ffmpeg -f lavfi -i aevalsrc="sin(440*2*PI*t):s=48000" -t 300 -y sin.flac git clone git://source.ffmpeg.org/ffmpeg.git || true pushd ffmpeg for REV in 16f9f7b n3.0 do if [[ -e ../ffmpeg_$REV ]] then continue fi git checkout $REV git clean -dxf ./configure make cp ffmpeg ../ffmpeg_$REV done popd for REV in 16f9f7b n3.0 do time ./ffmpeg_$REV -i sin.flac -acodec aac -strict -2 -y \ sin_${REV}.aac done _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
