Too high video bit rate.... again

Been researching this issue and basically, DVD SP4 assumes that it is the video rate which is too high even if the error is being caused by something else. Essentially, the combined bit rate of one video track, all audio layers and all subtitle layers must not exceed 8Mbps (if using 5 angle streams or less). Therefore, with the two uncompressed WAVE file layers encoded using 1536kbps each (standard 48kHz, 16 bit) or effectively 1.5Mbps and with the AC3 layer encoded using 448kbps, or approx. 0.5Mbps, this gives a combined rate of 3.5Mbps, only leaving 4.5Mbps maximum for the video stream. Having the audio all encoded to AC3 solves this issue, which is what Apple recommend and this also then makes the files adhere to the standard DVD spec.

Have ordered the Apple Training Book on DVD SP4 which looks a good read.

"Too high video bit rate"

A group of students ran into an issue yesterday when burning their final multi-audio layer DVD for their Audio Post Production coursework. The brief is for the students to create a 3 minute soundtrack for some original or found footage but there must be three audio layers: stereo mix, stereo mix with commentary and 5.1 ac3 mix. For some reason the DVD project in DVD SP4 would not build and the error message "too high video bit rate" kept on appearing. Firstly I tried lowering the maximum bit rate within the encoder section of the preferences window; no joy. Next I tried compressing their video file into an m2v file in "COMPRESSOR" so that no transcoding was required within DVD SP4; still no joy. Next I tried converting their audio files into AIFF 48kHz 16 bit files (even though they were already in this format); still no joy.

Finally I tried building the disc with just the main stereo audio layer - hooray, success! However, this was no good since they need to have three audio layers to accompany the video stream? I next tried just the main stereo stream with the 5.1 ac3 stream - hooray, even more success! What about just adding the main stereo and stereo with commentary layers I hear you ask? No joy! Therefor, for some reason DVD SP4 would not build the DVD when it had two uncompressed audio layers even though I have done this and demo'd this many times successfully?

Any how, the only option was for me to convert the uncompressed stereo with commentary file into 2.0 ac3 (using the Dolby Digital Professional 2.0 preset within COMPRESSOR) and then to re-import this into DVD SP4. Now, with the uncompressed stereo mix on layer 1, ac3 stereo with commentary on layer 2 and 5.1 ac3 mix on layer 3, everything worked fine. This is slightly frustrating however since I wanted the students to submit uncompressed versions of their two stereo mixes. Very strange?

Summer Schools

Already have got four different summer school type activites lined up to take place over the next couple of months or so. Should be good as the ADR sessions always go down well - think I will do something new this year, perhaps a scene from something like Monsters Inc; should go down well with the kids.