VLC needs to play incomplete files fragments

[Aeneas]

When downloading a file in any sharing context, the file segments comes in in fragments.
Since downloading shared files can often take weeks or even months, it is essential that VLC be able to parse through a file, find the existing downloaded fragments, and play the fragments within the file.

Currently, VLC is capable of playing the beginning of the file and then nothing else until perhaps the last 5% of the file.
Whatever VLC is performing at the end of the file needs to be performed all the way through the file to allow the downloader to verify that he is downloading the true file he thinks he is downloading, and in the right language, etc.
Year after year, this problem in VLC remains unfixed.

In fact, some files, the original source is lost, it is impossible to download the whole file and thus the user can only expect to ever receive a collection of fragments of the file. The program must be able to search the file, for the fragments within the file, find the headers of the YUV blocks of data and display every scrap of video and audio data it can find.
I would like to see VLC developers stop everything else and fix this Bug, before adding anything else.

[VLC_help]

You just can't play all incomplete files nor fix them completely. And it isn't a bug. For incomplete AVI files, there are some tools that try to fix these issues (like DivFix++), which you should try.

[Aeneas]

You can play these files, and as I have described, the VLC code does parse the last 5% of the file somehow and find the audio and video blocks in that last portion of the file and renders them.
The developers need to look at why the last 5% of the file is parseable and then propagate that solution throughout the playback of the whole file.
Fixing the file is not a solution.
A high proportion of files which are downloaded are downloaded through filesharing services.
Files are downloaded fragment by fragment. And sometimes they are not and never completely downloaded.
While these services are taking weeks or months to download a file, they allow a "preview" capability on any pending download.
VLC needs to be able to display as much A/V information from the fragments within the downloading file as possible.
I assume the VLC developers are simply not aware of how important and necessary this functionality is.
I hope they realize now, and will not expend any more man-hours on anything else until this problem is addressed.

I just downloaded the current version of the product, (first time in about a year) and found it full of bugs.
The Convert functionality still does not work and appears to have worsened.
In addition, Capture from a Tuner caused my pc to crash and reboot.
The changes seem to be cosmetic and there the effect has been to make the display footprint of the program bigger, which interferes with other operations on the desktop, especially when 'more than one instance' is enabled (not the default).
In fact, there are 2 checkboxes in Preferences which affect this instance issue which generate confusion and which indicate that the developers and their testers simply do not use the program.

[VLC_help]

Capture from a Tuner caused my pc to crash and reboot.

That is issue of your device drivers or hardware. Not issue of VLC.

Most P2P programs first download chunks from beginning and from the end because it helps verification of file using external programs. If VLC can show the last 5%, then the last 5% is downloaded completely. And with certain container formats (also applies to certain codecs) you cannot make anything useful out of certain fragments or GOPs if their packet header isn't there or I frame is missing. And without fixing the files, you cannot for example fast forward properly.

And did you try nightly builds?

[Aeneas]

Clearly, VLC is not invoking the Tuner driver(s) in a correct and secure manner.

Even when files are between 40 and 95% full, VLC fails to find contiguous data in the file, the existence of which is obvious from the graphicalization of the client software that is used nowadays. Generally these programs download in approximately 9.3 MByte blocks. There is a huge amount of contiguous data in 9.3 MBytes.
There is clearly a bug in the scanning of the file in VLC.
Windows Media Player does not do any better, but Microsoft is not expected to develop software which is attuned to the needs of the sharing context. VLC is targeted at that marketplace.

Fast forward is not important here, but the user should be able to mouse click on the VLC progress bar to reach an area that the user knows has much contiguous data, from looking at the graphicalization in the sharing program.

What about nightly builds ?

[The DJ]

1: We dont' NEED to do anything
2: Open source means: patches welcome, it does not mean: " bunch of idiots doing a lot of work for YOU in their free time, for free"
3: You are trying to play something that is broken !!!! it's as simple as that. why do you expect it to work ? If you have a brick house and you take one wall and start taking bricks out randomly, you cannot expect to have it work as a wall anymore. An mkv file is a brick wall, it's not a river.

[Aeneas]

1) It is up to the developers to decide what they are about.
2) Disparate software developers working for the common good.
3) An incomplete file is not broken. Not corrupted.
There is a lot of useful information in there which needs to be parsed.
Skip the empty spaces, look for I-frames then start generating video and the related audio.

[The DJ]

1) It is up to the developers to decide what they are about.
2) Disparate software developers working for the common good.
3) An incomplete file is not broken. Not corrupted.
There is a lot of useful information in there which needs to be parsed.
Skip the empty spaces, look for I-frames then start generating video and the related audio.

3 is not that simple. If you don't know where you are in an mkv file, it's very hard to find a good starting point again.

[VLC_help]

Clearly, VLC is not invoking the Tuner driver(s) in a correct and secure manner.

It is job for device driver people to make drivers that cannot be crashed or when they crash, they don't nuke down whole OS. VLC uses standard APIs for capture devices so no black magic here.

9.3 MByte blocks, you use emule? Have you ever tested VLC emule plugin?

One can easily have bigger I frame caps than 9.3 megs, specially with HD video.

Nightlies should have better working Conversion (specially x264 encoding) so that is why I suggest to try them and if conversion still doesn't work, you can open a trac ticket for it.

[Aeneas]

1) It is up to the developers to decide what they are about.
2) Disparate software developers working for the common good.
3) An incomplete file is not broken. Not corrupted.
There is a lot of useful information in there which needs to be parsed.
Skip the empty spaces, look for I-frames then start generating video and the related audio.

3 is not that simple. If you don't know where you are in an mkv file, it's very hard to find a good starting point again.

Are you saying that the average downloaded file will be encapsulated in Matroska format ?

[Aeneas]

Clearly, VLC is not invoking the Tuner driver(s) in a correct and secure manner.

It is job for device driver people to make drivers that cannot be crashed or when they crash, they don't nuke down whole OS. VLC uses standard APIs for capture devices so no black magic here.
9.3 MByte blocks, you use emule? Have you ever tested VLC emule plugin?
One can easily have bigger I frame caps than 9.3 megs, specially with HD video.
Nightlies should have better working Conversion (specially x264 encoding) so that is why I suggest to try them and if conversion still doesn't work, you can open a trac ticket for it.

What does the VLC Emule Plugin claim to perform ?
Rubbish. There are video clips of a full minute or two which are only 9 MBytes long.
Most shared video is not high bit rate/resolution.
No idea what a Nightly is. A new untested version of the program ?

[The DJ]

There is a reason we don't officially support that plugin.

[VLC_help]

http://nightlies.videolan.org/
latest builds. They usually have the latest patches.

[Aeneas]

I experimented on generating 1 second outputs from Windows Movie Maker 2 (which must contain one I-frame):

2.1 Mbps ---- 287 KBytes ---- 640x480
1.5 Mbps ---- 209 KBytes ---- 640x480
1.0 Mbps ---- 154 KBytes ---- 640x480
768 Kbps ---- 115 KBytes ---- 640x480
512 Kbps ----- 87 KBytes ---- 320x240
340 Kbps ----- 69 Kbytes ---- 320x240
150 Kbps ----- 31 KBytes ---- 320x240
048 Kbps ----- 17 KBytes ---- 160x120

These are very minor amounts of data to represent a full picture.
In addition, there are minor amount of P-frame data and Audio in each of these WMM2 outputs.
Perhaps the most common Internet high quality data rate is around 1 Mbps.
It is up the video encoder of course, but encoders targeted at this sharing marketplace should insert an I-frame at least every 5 minutes of video playback.
Using these figures as a general yardstick, over a 100 minute clip, a 5 minute I-frame rule would cost approx. 20 * 154KBytes = 3,153,920 Bytes (~3 MBytes) extra, over the 700 MBytes normally shared.

[VLC_help]

So you have issues with playback of incomplete WMV files?

[Aeneas]

So you have issues with playback of incomplete WMV files?

No. They are mainly .mpg and .avi . Actually, I find that whenever I download a .wmv, usually accidentally, 90% of the time it displays garbage on the screen.
However, the density of I-Frame video information should be comparable across the specifications.

[wexins]

lets say VLC is receiving the packets and couldnt make a picture to decode it because there is no pakcet which has EOF...
I am using mjepg decoder....if there is no EOF then what VLC is doing for that just loosing frame?
because if vlc is getting all packets and unwrap them (via live555 rtp) but coudlnt make a picture then this is just a loosing time....
how i can prevent it or what does vlc do for this situation????

[VLC_help]

wexins: you should open own topic for your issues/questions.