transcoding to mp4
Posted: 30 Oct 2006 20:41
by trek1413
In the transcoding module, you have the option to set the
video bitrate. In the case of mp4v, I'm under the impression
that the encoding is done with a variable bitrate. So, would
the video bitrate specified be the maximum bitrate?
Also, is there anywhere where I could find more information
about the mp4 encoding process?
Posted: 30 Oct 2006 22:22
by DJ
It's the Average bit rate or ABR.
GPAC! Try searching MP4Box on the web. This will provide info about the MP4 container but not the format (MP4v or MP4a) which is a part of the MPEG specification available from the MGEG group.
Be aware that there are many implementations of this. For example XviD, DivX, 3ivx, Sorenson to name a few (most common) all claim compatibility and many of them will play each others files to try to prove it. But in most cases they also prove that theres is better because the others do not play as well. The reality here is they are all different and the best results are obtained by using the decoder associated with any encoder for any of these MP4 file types. VLC tries to hit the middle of the road and does reasonably well for all the types, except when it comes to the encoder which seems to be best with 3ivx or Sorenson decoders outside of VLC's own decoder. In this case I believe FFMpeg does it all for VLC.