3 ms·
The term you are looking for is ‘random access point’. This property is more a function of the encoding parameters of the video stream. It just happens that M
by anonuser123456 3y ago
The term you are looking for is ‘random access point’.
This property is more a function of the encoding parameters of the video stream. It just happens that MPEG-TS is typically encoded so as to minimize the reasonable time between RAPs.
Also, MPEG-TS streams have sync bytes every 188 bytes, making it trivial to align the bitstream and then find the RAPs. Basically the use case you are describing is just the normal operation of a broadcast decode; get a stream at some arbitrary point of broadcast and decode it.
- izacus 3y agoIt's also a property of TS being designed for exactly this use-case, which is why it has these sync bytes and mechanisms to allow decoders to randomly access the stream and still get all the necessary data.
- alephnil 3y ago> This property is more a function of the encoding parameters of the video stream Not really. Formats like mp4 can't be parsed without reading the container header, that may be at the start or end of the file. Thus you can't read an mp4 by starting in the middle without reading the header and then seek to the middle of the file. This is the case regardless of encoding parameters. With mpeg-ts on the other hand, you can seek to a random place in the middle, and recover the stream on the next Iframe. Not many other file formats allow this.
- kuschku 3y agoOf course you can start an mp4 at an arbitrary point, that's what fragmented mp4 is for :) It's just lots of independent separate mp4 files concatenated into a single file.