Burning H.264 .m2ts to AVCHD DVD

[Ken Berry]

I have now downloaded the files, but have a preliminary question. Like Trevor, I cannot play the mp4 file -- at least in X4. In fact, it caused X4 to crash. But the other two -- the .ts original and .m2ts mpeg-2 with H.264 coding and no bitrate indicated -- would play. However, both have a rapid, stroboscopic effect in green, of all things, and I wonder if either Gary or Trevor had a similar experience?

As for the mp4 file, I tried playing it in Windows Media Player, the DivX player and, changing the mp4 to .mov, in the Quicktime player. All three simply said they could not recognise the file. And as I already said, X4 crashed when trying to insert it.

I will in the meantime continue to play with the files and will report back any further findings...

[garywood84]

Thanks, everyone, for your helpful input on this. I think the bitrate is less than 18Mbps, but I could be wrong. The thing is, that VSX4 won't let me burn the files to bluray either, so even if there is an issue with bitrate preventing me from burning AVCHD DVD without re-encoding, then there must be another issue as well.

[Ken Berry]

I am still puzzled by the mpeg-2 thing. Normally, an AVCHD file with the m2ts extension would be identified in VS Properties as a Microsoft HDMV file, not either an mpeg-4 file or an mpeg-2. So it could be a tag in the file (inserted by ReDo?) which VS is having difficulty with...

[garywood84]

As far as I know, VideoRedo isn't changing anything about the file when it outputs it. But it could be, and the problem is, I've no way to be sure, because the files from BBC HD don't work in VSX4 -- or any other video editor -- until they've had the second audio stream stripped out. So you can see this, and in case you have other ideas for things to test, I've uploaded a 10 second random capture from BBC HD that hasn't been edited at all -- it's just a capture of the stream exactly as it was broadcast:

http://dl.dropbox.com/u/19733878/BBCSample.zip

[garywood84]

Sorry, Ken - our posts crossed, I think, and I missed this one earlier.

However, both have a rapid, stroboscopic effect in green, of all things, and I wonder if either Gary or Trevor had a similar experience?

Yes, until I turned of Hardware decoding in VS properties.

As for the mp4 file, I tried playing it in Windows Media Player, the DivX player and, changing the mp4 to .mov, in the Quicktime player. All three simply said they could not recognise the file. And as I already said, X4 crashed when trying to insert it.

I wonder if the problem is that the files are MPEG2. The reason I think they're not is that BBC HD is supposedly broadcast in H.264 MPEG4 format (Wikipedia and several other sites confirm this), and Hauppauge -- the manufacturer of the TV card I used to capture the video -- says that it's cards capture the stream as broadcast.

[Ken Berry]

Well, whatever they are, VS is certainly seeing them as Blu-Ray mpeg-2, even if encoded with h.264. It is possible that Video ReDo has, in outputting .m2ts from a .ts original added a Blu-Ray flag as being consistent with the .m2ts wrapper extension. But it seems that VS sees it that way. So both that and the lack of any bitrate data are probably what is causing VS to stick.

Anyway, I have done a couple of things. First I opened the burning module to burn an AVCHD disc with an empty timeline and inserted your .m2ts file. I then pressed Next, and it went through the menu and preview pages. But when I tried to get to the burning page, the program crashed. So I reopened and tried it again, this time even trying to insert the .m2ts file into the burning timeline caused a crash. So I gave up on that.

I then opened the Editor and inserted your m2ts in the timeline. I didn't do anything to it. I then selected Share > Create Video File > AVCHD. The burning module opened with the *project* file (containing only your one video) in the burning timeline. I then proceeded through the menu and preview pages and got to the burning page with no problem. I de-selected the burning of a disk and select 'AVCHD Folder' instead. I clicked Burn and the process started with a message saying it would take some time to render. It then completed the render and built the AVCHD folder successfully. It plays smoothly in my various software players (PowerDVD and ArcSoft) and the flickering green had gone. The quality also seems to be very good. So that is one possible workflow for you to follow.

I could also extract the video from the AVCHD folder (00000.m2ts) and this time VS Properties told me the file was a Microsoft HDMV file, and with a max bitrate of 15 Mbps. So that was an advance in the sum total of our knowledge!

I also, separately, inserted your m2ts in the Editing timeline, and then selected Share > Create Video File > Same As First Clip. It fairly quickly produced a new file which again played smoothly and with good quality (and no green). And its properties also showed a bitrate of 15 Mbps, though it described the format (unsurprisingly) to be the same as the original: mpeg-2 transport stream. Interestingly, it did not indicate whether it was Upper Field First or Frame-Based -- the same as your original. But this might indicate another possibility -- that it is fully progressive. In a separate thread, I am dealing with 50p AVCHD, and its properties show it to be HDMV, but with no Field Order or reference to Frame Based either.

Anyway, I then cleared the Editing timeline and selected Share > Create Disc > AVCHD. I then inserted the new file into the burning timeline and this time had no trouble proceeding through the authoring process to the final burning page. Again I selected the AVCHD Folder option, and again I got the msg about it taking a long time to render. But it completed successfully, and again plays smoothly and with good quality. The extracted video describes itself as PAL HDMV and it is, not surprisingly, Upper Field First, with the same bitrate of 15 Mbps. So there is a second possible way of producing your hybrid AVCHD disc. While this re-rendering inevitably causes some quality loss, if you maintain the same bitrate as the original, any quality loss is unlikely to be detectable to the naked eye (I hope!!! )

[garywood84]

Hi Ken,

Thank you for going to so much trouble over this, and I'm sorry for the delay in replying to thank you.

I've tried out your solutions, and you're right that there's no noticable difference in the quality after the re-encoding, so that definitely provides one solution. That said, reduction of quality wasn't the only reason I wanted to avoid re-encoding: there's also a time implication too in that it takes much longer to author the disc if the video has to be re-encoded first. But, if that's the only way I can make this work, then it will have to be, and at least I can actually make the discs now -- after over a year of trying!

I'm still quite curious as to why this has proved so problematic, and I've also been in dicussion with VideoRedo users about it, over on their forum. I've had a rather interesting reply today, which suggests that the reason some programs are seeing the files as MPEG2 is because TS standard is part of the MPEG-2 specification. They go on to say...

My guess as to why your video needs to be recoded is due to a lack of IDR and/or infrequency of IDR frames. BluRay calls for an IDR every second. This allows for proper FF/RW functionality. Broadcasters assume you're watching live so they don't need IDRs nearly as frequently. Instead of IDRs they use I frames with SEI entry points, or sometimes they use flags in the original TS stream itself to designate entry points rather then using an SEI in the stream itself. Neither of these techniques is technically compatible with the BluRay spec and is probably why your software is trying to force a recode.

Now, I confess I don't understand all the terminology used there, but I think the long and short of it is that they are suggesting that the files are of the right type for bluray, but they are NOT formatted in a way that's compliant with the strict requirements of the format.

That made me curious, because I've noted in trying to find a solution to this that there are a number standalone bluray recorders on the market that claim to be able to capture DVB-S(2) and burn it to disc exactly as broadcast and without re-encoding it. When I raised this question over at VideoRedo, some members suggested that these devices may just burn the files to disc even though they don't strictly comply with the bluray standard, and that most players would be happy with them anyway.

So, it seems that the ideal solution to my problem might be piece of software that would create a menu for a bluray disc, and allow me to proceed through burning with files that weren't strictly bluray compliant, as long as they were H.264 MPEG4. Since such software doesn't -- to my knowledge, at least -- exist, I think I'll have to settle for your re-encoding solution for now (or perhaps re-encoding with VideoRedo, since it allows this to be done as a batch process, so I can at least cue up a whole set of files to be re-encoded one after another) and then burning those re-encoded files to bluray with VSX4.

Thanks again for all your input on this, Ken. I really appreciate it, and if you have any final thoughts on what I've said here, please let me know!

Gary