Where do different media files keep their index?

[SledgeHammer_999]

First of all, I am not sure that this the correct forum section please move it if it isn't.

I was wondering how each media file(mkv,mp4,avi,ogm,mp3,aac,flac etc) stores it's index file?
Does it store it at the beginning or at the end of the file?
How big is the index in size? Is it proportional to the size of the file?
Is there a list of all these info?(probably not)

[Mosu]

Matroska and MP4 files can store the index either at the front or at the back. Where it is stored depends on the muxer implementation. For Matroska it's stored mostly at the end of the file; for MP4 files I've usually seen it at the front (in MP4 you have all header stuff in one place including the index while for Matroska you can have track headers at the front and the index at the back). In both cases indexes grow more or less linearly with file size (for Matroska: with number of frames to index which are mostly only the key frames, with MP4: all frames).

Several other formats like Ogg/OGM, MP3, AAC, AC3 do not have indexes at all.

[SledgeHammer_999]

Hmmm maybe I am wrong and I don't really need the index info. Because I am unfamiliar with terminology, here is what I want to do. I contribute to a certain open source bittorent client. This client offers to download the first and last pieces of the torrent so it can be played back before it is fully downloaded(ie partially downloaded). In most cases this works as expected, but there are some cases where the piece is smaller than the index(?)/header(?), so the software player cannot read the necessary info about the file and cannot play it. In order to fix this, I thought that we might increase the number of pieces to download depending on the file...

So for what info should I ask? Is this easily available/searchable?

[Guest]

Can't help you with any torrent activities, per forum rule 6. Thread closed. If you think this was closed in error, please send me a PM with an explanation. Remember the onus is on you to show that everything is legit.