How do you navigate within a video file?

[vl6000]

I am trying to play a video file with extension .ty, using VLC 0.8.5 running under WinXP. I can play the file (size about 9.5 GB), but I can't control it very well. View/Stream and Media Info shows stream 0 codec=mpgv, and stream 1=mpga. These are the difficulties:

1) The time indicator at the bottom left shows the time elapsed / zero, rather than the length of the video.

2) The slider at the bottom controls the position in the video only for about the first 20 min, although the video is about 3 hours long.

3) None of the keyboard skips work, either forward or backward.

4) There is no way that I can find to back up; you have to start from the beginning.

5) The fastest I can skip is 8x normal, forward only.

Is there any way to do these seemingly elementary tasks in VLC?

[DJ]

I don't know about .ty files! But you are rather describing MPEG-TS. Depending on the encode there may be problems with seeking. This can be true of any format, but MPEG in general does not have good time information. Starting with VLC 0.8.5 MPEG times have been corrected and are almost proper.

Try cross checking this problem file with another player to see if it is the file (as I suspect it is) or it's a problem for VLC.

[vl6000]

Starting with VLC 0.8.5 MPEG times have been corrected and are almost proper.

But I'm using 0.8.5. And that doesn't explain why I'm limited to 8X normal speed.

Try cross checking this problem file with another player to see if it is the file (as I suspect it is)

The file does't play with either Windows Media Player 10 or Nero. But since the file is interpreted correctly by VLC, the navigation should also work. Even if there is no time information in the file, VLC can skip forward by processing the input stream faster than normal without display.

[DJ]

Unfortunately this is an improper assumption. The first sign of an improperly encoded video in any format is seeking problems. It isn't at all unusual for MPEG-TS because there are so many varying implementations. Most generally it's missing PAT/PMT tables. A player has no way to reconstruct this.

[vl6000]

Most generally it's missing PAT/PMT tables. A player has no way to reconstruct this.

First, if VLC can play the video (forward) at 1X, 2X, 4X and 8X, which it can in this case, it can surely read the file at higher speeds, if it does not have to display anything. That would allow implementation of the forward skips.

Second, there is nothing to prevent VLC from reading the entire file at high speed, and constructing any missing information.

Third, having played the video forward up to a point, VLC has already seen all the information it needs to skip backwards.

Without knowing the details of the missing information, I can assure you that, for a "proper" file, this information was constructed from scratch at some time in the past, by software. VLC could do the same.

[DJ]

Considering you are becoming an authority on this why don't give a hand at programming? Patches and additions are always welcomed here!

This may offer some helpful hints: http://www.erg.abdn.ac.uk/research/futu ... trans.html

It would also be neat to find another player to play your files if you can!

[vl6000]

Considering you are becoming an authority on this why don't give a hand at programming?

Because VLC seems to be a typical open-source product, which means to me

- The code is virtually uncommented.
- There are no overview documents.
- The package uses a complex and undocumented directory structure.
- The user documentation is rudimentary.
- The package is dependent on multiple libraries which have all the same problems.
- Figuring out how to get the software to build on any system is a big job, but especially on Windows, since the orientation of the developers is towards Unix-based systems.

All these mean that to make the simplest change will require at least a few weeks of study of the source code, and probably a lot more.

I am also guessing that help from other developers would not be available, as witness the fact that no one has stepped up and answered my relatively simple questions.

I don't mean to sound so harsh, but I have learned through sad experience how frustrating it can be to try to work on a large open-source project.

[DJ]

Once again a lot of assumptions! Have you looked at the developers section? Have you read ANY or the documentation? For the complexity of VLC I would say it's quite well documented and commented for an open source project.

Your questions have been answered here. A method of doing what you suggest, would be to index the file and store the index on disk. This would take (more or less) 10 min per hour of running video. At the moment the only files that are index corrected are AVI files in which the index has been damaged. Users have not responded to this well. It seems they are not willing to wait for VLC to do this and have requested a way to shut off the feature, which will be Incorporated in the next revision. Also the method of indexing varies for each file format and MPEG PS is different from MPEG TS. Actually given the structure of MPEG TS I'm not sure it can be indexed, which is why I provided the link.

If you want to pursue this try features requests or grab the source code and start digging.

[vl6000]

Have you looked at the developers section? Have you read ANY or the documentation? For the complexity of VLC I would say it's quite well documented and commented for an open source project.

I have to apologize on this one. I downloaded the sources, but didn't find any documentation included there. I did read all the user documentation I found, and it has a lot of details, but no overview.

Your questions have been answered here.

Only in the negative.

If you want to pursue this try features requests or grab the source code and start digging.

I may do so if I have time. Since I don't use gcc, gdb, or Linux, it will be a big job just to get the sources to build (as is noted in the developer docs).

[DJ]

I'm sorry you feel it was all negative. Part of the problems here are time and resources. It is after all a free project. I would like to see many things too and this becomes a rather long list and some what specialized with regard to the right person to do it.

Changes here take place through many users wanting the same thing or contributions. There is also a rather long wish list for changes we would all like to see not that users always respond well to them.

VLC is in the midst of a rather big change as the Main interface is being rebuilt and playlist sections are being rebuilt, subtitles again etc. Then there are projects that have never been finished like the AVI container used for transcoding or some of the filter modules used for transcoding. Some of the filters in general need updating and the MPEG TS module we are discussing needs to support Program tables considering the growth of DVB. Also we need support for the newer DVB drivers. The list goes on and time never stands still to do all the things we would like.