[PATCH] libnut muxer: write at least one timebase
This patch adds code to make sure that there is at least one timebase. Otherwise, creating a file without any stream would result in an invalid file, or the muxer would crash when trying to write max_pts in the index.
On Mon, Jan 22, 2007 at 02:24:07PM +0100, Clemens Ladisch wrote:
This patch adds code to make sure that there is at least one timebase. Otherwise, creating a file without any stream would result in an invalid file, or the muxer would crash when trying to write max_pts in the index.
Is a file without any streams valid?.. - ods15
Hi On Fri, Feb 02, 2007 at 11:10:32AM +0200, Oded Shimon wrote:
On Mon, Jan 22, 2007 at 02:24:07PM +0100, Clemens Ladisch wrote:
This patch adds code to make sure that there is at least one timebase. Otherwise, creating a file without any stream would result in an invalid file, or the muxer would crash when trying to write max_pts in the index.
Is a file without any streams valid?..
hmm, i think we havent thought about that ... at least such a file cannot contain any frames, stream headers or syncpoints and without timebases it cannot contain an (useless) index and info packets now the timebase less case really is useless because the only thing which you could store in the file would be the main header and possibly future new headers ... in the streamless but not timebase less case you could store an index which would contain nothing and info packets iam not sure if theres any use for that? seperating info packets from actual streams like providing just a info packet file for some other file, like providing detailed info for a dvd, so someone could take th dvd remux it to nut and add the info somehow ? [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB While the State exists there can be no freedom; when there is freedom there will be no State. -- Vladimir Lenin
On Fri, Feb 02, 2007 at 11:38:32AM +0100, Michael Niedermayer wrote:
Hi
On Fri, Feb 02, 2007 at 11:10:32AM +0200, Oded Shimon wrote:
On Mon, Jan 22, 2007 at 02:24:07PM +0100, Clemens Ladisch wrote:
This patch adds code to make sure that there is at least one timebase. Otherwise, creating a file without any stream would result in an invalid file, or the muxer would crash when trying to write max_pts in the index.
Is a file without any streams valid?..
hmm, i think we havent thought about that ... at least such a file cannot contain any frames, stream headers or syncpoints and without timebases it cannot contain an (useless) index and info packets
now the timebase less case really is useless because the only thing which you could store in the file would be the main header and possibly future new headers ...
in the streamless but not timebase less case you could store an index which would contain nothing and info packets iam not sure if theres any use for that? seperating info packets from actual streams like providing just a info packet file for some other file, like providing detailed info for a dvd, so someone could take th dvd remux it to nut and add the info somehow ?
I have no strong feeling on this. I would not be against a 'stream_count MUST be >0' ... - ods15
On Fri, Feb 02, 2007 at 11:38:32AM +0100, Michael Niedermayer wrote:
On Fri, Feb 02, 2007 at 11:10:32AM +0200, Oded Shimon wrote:
On Mon, Jan 22, 2007 at 02:24:07PM +0100, Clemens Ladisch wrote:
This patch adds code to make sure that there is at least one timebase. Otherwise, creating a file without any stream would result in an invalid file, or the muxer would crash when trying to write max_pts in the index.
Is a file without any streams valid?..
hmm, i think we havent thought about that ... at least such a file cannot contain any frames, stream headers or syncpoints and without timebases it cannot contain an (useless) index and info packets
now the timebase less case really is useless because the only thing which you could store in the file would be the main header and possibly future new headers ...
The spec explicitly forbids having no timebases.
in the streamless but not timebase less case you could store an index which would contain nothing and info packets iam not sure if theres any use for that? seperating info packets from actual streams like providing just a info packet file for some other file, like providing detailed info for a dvd, so someone could take th dvd remux it to nut and add the info somehow ?
In a video editor application, it would make sense to be able to save a file with some global metadata even when the user hasn't yet created any streams. If streamless files were not allowed, the program would have to create a dummy stream, or say "I'm sorry Dave, I'm afraid I cannot do that". Oded Shimon wrote:
I have no strong feeling on this. I would not be against a 'stream_count MUST be >0' ...
This change to the spec would not be backwards compatible ... ;-) In practice, it wouldn't make much of a difference if the error message of a media player would be either "I cannot play a file without any data" or "A file without data is not a valid nut file". Regards, Clemens
participants (3)
-
Clemens Ladisch -
Michael Niedermayer -
Oded Shimon