FFDShow's "on fly" AC3 decoding

[Digiface]

So if i have for example divx file with mp3 audio, is it a good thing to use ffdshow's AC3 decoding to decode mp3 to ac3? I have spdif passthrough.

[sneaker_ger]

No, as mp3 is only mono or stereo which can be send over spdif as uncompressed (hence lossless) signals. On-the-fly ac3-encoding would be useful if your video had audio which can't be used over spdif, like 5.1 channel flac or aac.

[Digiface]

No, as mp3 is only mono or stereo which can be send over spdif as uncompressed (hence lossless) signals. On-the-fly ac3-encoding would be useful if your video had audio which can't be used over spdif, like 5.1 channel flac or aac.

Ok. Thanks!