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| AC3 is usually preferred because it has a lower bit rate than AIF or WAV. DVDs play best on all players with a combined (audio + video) bit rate of around 7 Mbps. I forget off hand what uncompressed WAV and AIF are, but if you choose them, you have to adjust the video bit rate downward to accommodate the combined optimum ceiling. I think the limit for DVDs is 9 Mbps, but that will choke a lot of players and make them skip, or drop frames during playback. I've had good luck with 8, but that may be pressing it. So, 6-7 is the target I go for (for video when using AC3 audio), and don't often hear complaints about playback issues from clients. In my experience, the more expensive the DVD players are more sensitive to playback skipping. I've had fewer issues on cheaper players than the high end models. On Aug 8, 2013, at 7:54 AM, Chris Zwar <chris@chriszwar.com> wrote: > On 08/08/2013, at 10:08 AM, Jeanette Barekman <jsbarekman@yahoo.com> wrote: >> Would like to know what are the pluses for using an AC3 file. > > AC3 is the Dolby Digital codec used on DVDs. It's a compressed format, in the same way that MP3s and AAC (iTunes) are compressed files, however AC3 was specifically designed for 5.1 surround sound. It supports a range of channels - including stereo and 5.1 - and the bitrate can be adjusted to balance file size and quality. On DVDs it's always 48K, but I think in software it can handle different sample rates. > > WAV and AIFFs are uncompressed files, taking up roughly 600meg for 1 hour of stereo audio. If a DVD used uncompressed audio then a 2 hour feature film with 5.1 surround sound would need 3.6 gig just for the audio tracks, which is pretty pointless as a single layer disc only holds 4.3 gig in total. > > On paper DVDs support a few different types of audio, but in general AC3 IS the DVD audio standard. Commercial DVDs that don't use AC3 for audio are extremely uncommon. > > > -Chris > > > +---End of message---+ > To unsubscribe send any message to <ae-list-off@media-motion.tv> |
