Why does mpeg4 file use so much dvd space?

[Darth Porno]

i have a 485 mb 48 min mpeg4 file that i encoded on ffmpegx but when i drag it into toast it shows it using most of the space on a 4.7 gb dvd? i have 13, 45 min episodes of a tv show and i have to use 12-13 dvds? that doesn't sound right. any help is appreciated. i used the default avi to mpeg4 settings in ffmpegx. i tried using the avi to dvd setting to make video_ts folders because it looks like toast would burn 3 episodes that way but everytime i try to use those i wait forever for toast to encode them again and i get error code 18768 and it fails to burn.

[DeusExMachina]

DVD specs do not allow for MPEG4 playback. To make the DVD, toast must re-encode to Mpeg2. As such, the file sizes are going to be MUCH bigger. If your average bitrate settings in toast are also set high, that can lead to huge m2v files for toast to burn. You should have used ffmpegx to encode to 352x240 mpeg2 files with 48k audio for minimal file sizes allowed by the DVD specs.

[Darth Porno]

Thank you. that was very helpful.

[Darth Porno]

ok, i just encoded an episode using dvd mpeg2enc setting with the video set at 352x240. the result was it created 3 mpeg files along with a video_ts folder. one of the mpeg file was audio only and when i played the video_ts folder on dvd player there was no video only audio. also the origanal avi file was 42 mins but when i drag the video_ts folder into toast, it shows the file to be only 21 mins. god i'm a total noob.

[DeusExMachina]

One thing you can do to maximize space is to use MPEG2 352x240, as I said. However, ffmpegx is not very helpful here. While the DVD spec allows this resolution in both MPEG 1 and MPEG2, there is no preset in ffmpegx to do this. Instead, use the DVD ffmpeg preset. Next, in the video section you will see that the size is set to 720x480 (another reason for your huge files.) select VCD from the Autosize: pop up. This sets the size correctly (making sure that the framerate is set correctly (NTSC 29.97 in the US). Then adjust the bit rate until it shows as green. It will probably initially read 4000 kps. Click in this field, then in another one. This value will now turn blue, indicating that the bit rate is too high. Adjust downward, starting at around 1000 kps and repeat this procedure until it turns green. If it goes red, you have gone too far.
Next go to the audio section and set to .AC3 (for minimal file size with maximum sound quality.) Set bitrate for nothing higher than the bitrate of the original file (from the summary section) and MOST IMPORTANTLY a Sampling rate of 48000 Hz. Set to Stereo (5.1 files are huge and if you are not starting out with 5.1 media, useless) and either CBR or VBR.
In the options section, you may want to set it for High Quality, Two-pass encoding. I prefer to NOT use Quicktime to decode, but that is up to you. Make sure encoding profile is set to DVD, and uncheck Author as (since you are using toast) then click encode. Drag the files to toast and burn as Video_TS.

You can, of course, also use ffmpegx to make the TS folders without toast. Then just drag and burn.

[Darth Porno]

ok, anytime i've tried to use video_ts folders that i encoded in ffmpeg and then dragged into toast dvd-video(multiple video_ts folders) i've gotten error code 18768. i'm sure if i dragged it into dvd from video_ts it would work fine but i want to put multiple episodes on one dvd. please forgive my noobness but i don't know how to make a video_ts folder in toast never have done it before.

[Case]

Then adjust the bit rate until it shows as green. It will probably initially read 4000 kps. Click in this field, then in another one. This value will now turn blue, indicating that the bit rate is too high. Adjust downward, starting at around 1000 kps and repeat this procedure until it turns green. If it goes red, you have gone too far.

Or use the 'Best' button to get a good bitrate based on the current framesize and framerate.

[Darth Porno]

allright this is what i did, encode avi to ffmpeg dvd 16:9, adjusted video bitrat until it was in the green, set audio to ac-3, set audio bitrate to 192(same as origanal avi), authered it as video_ts, checked high quality and two pass encoding boxes, then encode. now waiting. i'll encode two more episodes in the same way. then i will drag all of the video_ts folders into toast dvd-video and it should work right? also, what is the extra mpeg file lef over that's not in the folder thats created and do i need to do anything with this file?

[Case]

Imho, in Toast, you could better use the .mpg files than the VIDEO_TS folders, if you plan on bringing several encodings together on one DVD. The latter is created from the first. As mentioned earlier, if you de-select Author as, then ffmpegX won't create the VIDEO_TS structure, saving you some time and disk space in the process.

[DeusExMachina]

Yeah, don't use the VIDEO_TS folders if you are using toast in that way. The DVD spec expects ONE and only one VIDEO _TS folder (some anal retentive players also require an empty AUDIO_TS folder.) So if you need multiple episodes, deselect the Author as option, and just drag the encoded mpeg files into toast. Since you have already done it, wait until you are finished, delete them, then just drag the mpeg file (or m2c and ac3 files.)