|*||The library which handles AVI files in transcode(1) can read such index files and use this file to rebuild the index instead of scanning through the whole AVI file over and over again. Reading the index from the index file is much faster than scanning through the AVI.|
|*||It can be used as a seeking file. When given to transcode via the --nav_seek switch, transcode will use the file to seek directly to the position you specified via -c. This also works for multiple -c ranges.|
|*||Its nice to have for debugging.|
-o ofile Specify the name of the output file. -i ifile Specify the name of the input file. -f force the use of the existing index. -n force generating the index by scanning the file. -x (implies -n) dont use any existing index to generate keyframes. -v show version. -h show help text.
aviindex can convert from and to mplayer-generated index files. Since mplayer-1.0pre3 mplayer has the ability to save the index via -saveidx FILE and load it again through -loadidx FILE. aviindex is able to convert an mplayer index file to a transcode index file and vice visa. It is not able to directly write an mplayer file, though. Example of a toolchainmplayer -frames 0 -saveidx mpidx broken.avi aviindex -i mpidx -o tcindex avimerge -x tcindex -i broken.avi -o fixed.aviOr the other way roundaviindex -i broken.avi -n -o broken.idx aviindex -i broken.idx -o mpidx mplayer -loadidx mpidx broken.aviThe major differences between the two index file formats is that the mplayer one is a binary format which is an exact copy of an index in the AVI file. aviindex 's format is text based. See FORMAT for details.
aviindex -i 3GBfile.avi -o 3GB.index
generates and index of the large file 3GBfile.avi. You can use the file 3GB.index to tell transcode to read the index from this file and not from the avi. This leads to much faster startup time.
Suppose 3GBfile.avi has DivX video and PCM sound and you want to encode several ranges.
transcode -V -i 3GBfile.avi --nav_seek 3GB.index \ -x xvid,avi \ -c 5000-6000,0:20:00-0:21:00,100000-100001 \ -y xvid --lame_preset standard -o out.avi
The format of the index file. The first 7 bytes in this file are "AVIIDX1" for easy detection and a comment of who created the file. The second line is a comment and describes the fields. Do not delete it. Each line (except the first 2) consists of exactly 8 fields all seperated by one space and describing one particular chunk of the AVI file.
Here is an example of an AVI file with two audio tracks.The field TAG is the chunk descriptor. Its "00d*" for the video, "01wb" for the first audio track, "02wb" for the second audio track and so on.
AVIIDX1 # Generated by aviindex (transcode-0.6.8) TAG TYPE CHUNK CHUNK/TYPE POS LEN KEY MS 00db 1 0 0 2048 8335 1 0.00 01wb 2 1 0 10392 847 1 0.00 01wb 2 2 1 11248 847 1 0.00 02wb 3 3 0 12104 847 1 0.00 02wb 3 4 1 12960 847 1 0.00 00db 1 5 1 13816 5263 0 0.00 00db 1 6 2 19088 3435 0 0.00 01wb 2 7 2 22532 834 1 0.00
The field TYPE is the type of the chunk. This is redundant because the type is also embedded into the TAG field but its a convenient thing to have. Its 1 for video, 2 for first audio track and 3 for second audio track.
The field CHUNK is the absolute chunk number in the AVI file. If you read the CHUNK field in the last line of the index file, you know how many chunks this AVI file has.
The field CHUNK/TYPE holds information about how many chunks of this type were previously found in the AVI file.
The field POS is the absolute byte position in the AVI file where this chunk can be found. Note this field can hold really large numbers if you are dealing with large AVIs.
The field LEN is the length of this chunk.
The field KEY holds information if this chunk is a keyframe. In the example above, all audio chunks are key-chunks, but only the first video frame is a key frame. This field is either 0 or 1.
The field MS holds information about how many milliseconds have passed. This field may be 0.00 if unknown.
aviindex was written by Tilmann Bitterberg <transcode at tibit.org>
and is part of transcode.
avifix(1), avisync(1), avimerge(1), avisplit(1), tccat(1), tcdecode(1), tcdemux(1), tcextract(1), tcprobe(1), tcscan(1), transcode(1), mplayer(1)
|aviindex(1)||AVIINDEX (1)||29th February 2004|