avc/.h264 problem

[phoenixfire]

I have some .mkv files that contain .mp4 files that I can not, for the life of me, figure out how to convert to avi. I"ve been able to convert .mp4/x264 files without a problem through avisynth and virtual dub. But these .mp4 files seem to be different, and I can't find anything to convert them. When I load them into YAMB to try to extract the elementary video file, it gives me an error; "ISOMedia file truncated". I've run these files through avc2avi, but no matter what codec I use (xvid, divx, x264) the file comes out about 30 seconds too long or too short for the audio.

Does anyone have any idea what is going on with these files and what I can use to get them to convert correctly to a format I can then use for DVD burning?

[celtic_druid]

mkv and mp4 are both containers. You don't put mp4 files in mkv. It is either one or the other. Both mp4 and mkv support VFR (Variable Frame Rates). This could explain why your video is too short as when you assume that something is CFR when it is VFR, its length no longer matches the audio.

avc2avi doesn't change the video. It simply remuxes raw h.264 streams to avi. Can't see the point anyway, it's not like you can play such avi's on SAP's or anything. If you want to convert to DVD video, then I would suggest you forget about avi and convert to MPEG-2.

[phoenixfire]

I didn't create the .mkv, that's the way it came. Right or not, that's the way it was done. And my reasons for wanting to convert this are not the issue. I can't convert the .mp4 to vob anyway, I get the SAME ERROR. What I'm looking for is help to fix this, not commentary on why.

How can I get this mp4 out to a raw stream then? As I said, YAMB can't extract it. Are there any other programs that could do it? Or is there a program that can convert the mp4 if it is VFR? Most of the programs that I've tried don't even recognize the mp4 as a video file, but gspot says it's a .h264/avc file and that it's an elementary video stream.

[celtic_druid]

If you have a mkv containing native AVC, then it is not mp4. It is an mkv containing native AVC. When you extract it you will get a raw H.264 stream. In order to extract with yamb, you would have to mux it first, which is just pointless.

You want a raw stream? You already got it.

[phoenixfire]

Let me rephrase the request then. I need the elementary stream in a form that I can use. Right now, as it is, it is useless to me. No program will touch it as it is. All players say there is no video stream. I can't serve it, as Haaili's Splitter blows up and give me the error "Invalid first byte of EBML ID: 00". ConvertxtoDVD won't touch it, giving me the "ISOMedia is Truncated" Error. And even MP4Cam2Avi, which I read on these forums as being able to convert any AVC file, gives me an error of "moov atom not found". AVC2Avi is the closest I've come to reencoding these files, but I seem to have a variable bitrate issue, as you've said. Do you have any idea why I keep coming up with these errors or if there is anything that can reencode these to a format I can work with? As I said, I've been able to convert 264/mp4 successfully before. These are the first files I've hit this wall with. I've been trying to find an answer for a long time in both these forums and in Doom9's, but no one else seems to have asked about this before.

[celtic_druid]

You have an elementary stream. Raw = elementary.

If you want to play it in players, I would suggest leaving it as an mkv. There are parsers that can handle raw h.264 streams though. Still that means just video. No audio.

You can't just treat a raw stream as an mp4. If you want an mp4 fir yse wutg mp4cam, etc. then you need to remux with mp4box/yamb. If it is indeed VFR, then you need to take the original time codes into account though and it still won't help you since you want DVD video.

As I said, mkv != mp4, so converting an mp4 sucessfully means nothing. My advice is to forget about avi, mp4, etc. and just convert the mkv to MPEG-2/AC3.

[phoenixfire]

I'm not treating as an mp4. That's how it comes out of the mkv when I run it through MKVExtract. "GS09-1.mp4" is the video file.

But, I don't care how it's converted. Converting files to Avi and running them through TMPGEnc is just the way I've always done it. What programs would you suggest for converting an mkv then? Avisynth won't work. Already tried ConvertXtoDVD. It won't read the video file (even though it says it can do AVC. What else can I try then?

[jliles]

Hi,

I've had similar exasperating problems trying to convert some anime fansubs encoded similarly to yours that I just wanted to get into a form that I watch on my TV using my dvd player. I used avc2avi as well and had problems with sound sync due to variable frame rates.

What was ultimately successful for me was to use Mediacoder to convert the file to an AVI and ensure that the audio was transcoded to CBR. Mediacoder can also convert directly to mpeg2, which I assume is what you want for DVD authoring.

Hope that helps
Julie

[celtic_druid]

Exension should have been .264, although it lets you set it manually and then stores it in Formats.txt.

AVISynth with directshowsource() doesn't work? If you can play the files via dshow it should.

Yeah, mediacoder should work since I believe it uses mencoder for encoding. Not sure how mencoder treats VFR mkv's though.

[phoenixfire]

Hi,

I've had similar exasperating problems trying to convert some anime fansubs encoded similarly to yours that I just wanted to get into a form that I watch on my TV using my dvd player. I used avc2avi as well and had problems with sound sync due to variable frame rates.

What was ultimately successful for me was to use Mediacoder to convert the file to an AVI and ensure that the audio was transcoded to CBR. Mediacoder can also convert directly to mpeg2, which I assume is what you want for DVD authoring.

Hope that helps
Julie

It did! It totally worked perfectly! I can't believe it even used the right audio file! That program just rocks! Thanks so much Julie. I have been pulling my hair out about this for sooooooo long. It's great to finally have a solution.

[phoenixfire]

Exension should have been .264, although it lets you set it manually and then stores it in Formats.txt.

AVISynth with directshowsource() doesn't work? If you can play the files via dshow it should.

Yeah, mediacoder should work since I believe it uses mencoder for encoding. Not sure how mencoder treats VFR mkv's though.

I really wish knew why when it was encoded, it came out as mp4. I would have saved me so much time and grief if it had been a plain, old .264. But, MediaCoder worked out perfectly. Better than I thought. It put the audio and video into perfect sync. You can set both to a constant bitrate, and it keeps things in sync.

Thanks for all the help. I still wish I had an answer as to why the video stream came out as it did. Just for future reference. But for now I'm happy just being able to convert these files. These boards have always come to my rescue, if it's just searching for an answer, or having to ask. Thanks a lot.