Rendering slide shows for DVDs - best parameters
Slide shows with transitions and music usually require coverting photos into a movie format. If you want to create a standard DVD (with menu authoring) from it, this will unfortunately be a trade off in quality. Standard DVDs only support 704 x 576 (PAL) or 704 x 480 (NTSC) pixels. With these resolutions, a series of JPGs would only consume 50K per picture. But unfortunately, the old MPEG2 standard for DVDs is not optimized for this situation. An MPG-bitrate of 4Mbps results in 500K per second - no matter if there is any movement on the screen. If you reduce the bitrate, results look awful. With my old Vegas Movie Studio (2012) I have tried a number of settings for the best acceptible results without wasting too much storage and space - because there is a limit of 4,7GB per single-layer DVD. These are the optimized settings:
| I-Frames | 32 | I-frames show the whole picture. A large number of frames between is useful to reduce filesize when there is no motion. 32 was the maximum. |
|---|---|---|
| B-Frames | 7 | I-frames show the whole picture. A large number of frames between is useful to reduce filesize when there is no motion. 7 was the maximum. |
| Field order | None (Progressive Scan) | This is the key setting to minimize pixel effects, especially for diagonal picture structures |
| Variable Bitrate | max 6M, avg 1M, min 192K | High variability: High rates at picture changes and transitions. During the stills no data required. |
| GOPs | open | uncheck closed GOPs for more data flexibility |
| DC coefficient | 10 bit | recommended by the software for situations without motion |
Using MP4 results are much better but not compatible with the standard DVD format. They still can be stored on a DVD - or use a USB stick or HDD as a file. Here, you can use the half-frame rate of 12.5 fps for motionless content. File sizes with the same bitrate are smaller in MP4. The table shows examples for 2Mbit average encoding:
| MPEG2 | 400 KB |
|---|---|
| MP4 | 300 KB |
For normal videos, I struggled a lot with the MP4 options. This could be Vegas-12 specific. Here are my clues:
- Using 1080p often results in stuttering. An encoder issue? 720p seems safer without too much loss in video quality (sufficient for home use).
- Use Progressive Scan
- Uncheck "adjust frame rate by source". If checked, I get only 15fps.
- The standard frame rates is NTSC (30 fps). PAL frame rate 25 fps is not supported though offered in the menu. Half-PAL with 12.5fps is possible (see above)
- Only the offered bitrates (768K/2M/4Mbit...) are valid. If you enter 3Mbit, it will encode in 2Mbit.