Sequential JPEG File Format

Description

The THPConv tool can convert a group of sequential JPEG files having sequence numbers at the end of their filenames (indicating the playback order) to THP movie data. When interleaving audio data in sequential JPEG files, you must either specify the WAV files by using the -s option at the time the sequential JPEG files are converted, or add the WAV files after conversion.
The following restrictions apply to groups of sequential JPEG files that can be handled with the THPConv tool.

- All JPEG files to be collected into a single THP movie dataset must have the same number of pixels in the horizontal and vertical directions.
- The group of sequential JPEG files must have sequence numbers (corresponding to frame numbers) appended to the end of their filenames.
- The number of the JPEG file corresponding to the initial frame of the THP movie data can be any number. However, the numbers of all files thereafter must be sequential.
- Please add leading zeros to the frame numbers appended to the filenames so that they all match the number of digits in the last frame.

The following restrictions apply to each file in a group of sequential JPEG files.

- Only the JPEG baseline DCT format is supported.
- Only sequential encoding is supported.
- Only 4:2:0 sub-sampling is supported.
- The pixel counts in both the horizontal and vertical directions must be a multiple of 16.
- The maximum pixel count in the horizontal direction is 672 dots. There is no restriction on the pixel count in the vertical direction.

If the sequential JPEG files do not meet these requirements, the THPConv tool will output an error and stop processing.

Example

To create four seconds of THP movie data at 30 FPS from sequential JPEG files, the numbers of the sequential JPEG files (testxxx.jpg) should look like the following:


Frame 1 : test001.jpg
Frame 2 : test002.jpg
Frame 3 : test003.jpg
… :
Frame 51 : test051.jpg
Frame 52 : test052.jpg
… :
Frame 118 : test118.jpg
Frame 119 : test119.jpg
Frame 120 : test120.jpg

See Also

THPConv.exe
Converting Sequential JPEG Files to THP Movie Data
File formats compatible with THPConv

Revision History

2006/03/01 Initial version.


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