Write and read text files describing the index of an AVI file
see also :
avifix - avisync - avimerge - avisplit - tccat - tcdecode - tcdemux - tcextract - tcprobe - tcscan - transcode - mplayer
[ -o ofile -i ifile -f -n -x
-v -h ]
add an example, a script, a trick and tips
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
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
writes a text file describing the index of an AVI file. It
analyses the content or index if available of the AVI file
and prints this information in a human readable form.
An AVI file can
have an optional chunk called "idx1" which
contains information about keyframes (syncpoints) and
locations of video frames resp. audio chunks. Though larger
AVI files (>2-4GB), so-called OpenDML AVI or also AVI 2
files, have a more complicated indexing system, which
consists of a superindex referring to (possibly) several
"standard" indexes, the "indexing
principle" is the same. Movie players use such indexes
to seek in files.
reads the AVI file ifile and writes the index into
ofile. This can either happen in "dumb"
mode where aviindex looks for an existing index (and
trusts this index!) in the file and dumps this index into a
human readable form. The "dumb" mode is used, when
-n is NOT specified or when the filesize of the input
file is smaller than 2 GB.
"smart" mode, aviindex scans through the
complete AVI file and searches for chunks (may that video or
audio) and reconstructs the index based on the information
found. If an index chunk is found accidently,
aviindex will use the information in this index to
recover the keyframe information, which is important.
aviindex will use smart mode, if given the -n
option OR if the AVI file is larger than 2 GB. If the file
is large, the index chunk cannot be found the usual way so
one must use -n but it is possible that there is an
index chunk in this file. Cross fingers.
Also in smart
mode, aviindex analyzes the content of the video
frame and tries to detect keyframes by looking at the data
depending on the video codec.
index file serves different purposes.
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.
Specify the name of the output
Specify the name of the input
force the use of the existing index.
force generating the index by scanning the file.
(implies -n) don’t use any existing index to
show help text.
aviindex is Copyright (C) 2003,2004 by Tilmann Bitterberg
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.
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 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.
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 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
mplayer -frames 0 -saveidx mpidx broken.avi
aviindex -i mpidx -o tcindex
avimerge -x tcindex -i broken.avi -o fixed.avi
Or the other way round
aviindex -i broken.avi -n -o broken.idx
aviindex -i broken.idx -o mpidx
mplayer -loadidx mpidx broken.avi
The 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.
avisync , avimerge , avisplit ,
tccat , tcdecode , tcdemux ,
tcextract , tcprobe , tcscan ,
transcode , mplayer
was written by Tilmann Bitterberg <transcode at
and is part of transcode.