Why doesn't my camcorder play this mp4?

[Bencuri]

So my camcorder records in mp4. I stabilised the recorded videos in Mercalli, then I converted the output file back to mp4. I want to play this final video on my camcorder by connecting it to the TV. The problem is that this final mp4 cannot be played on the camcorder, it doesn't recognise the video. I used Xilisoft converter to make this file, I tried to set everything like the original, but it seems there is still something missing. Could you check the original and final mp4 and suggest what is still the problematic difference between the two file?

Here are they:

http://files.videohelp.com/u/212034/original.MP4
http://files.videohelp.com/u/212034/final.mp4

[Baldrick]

Most digital camcorders will only accept video it create itself. Maybe some special header or something.

[smrpix]

Different GOP structure and Audio Sample rate for two. Use Mediainfo
Very likely you'll never quite get this to work.

[Bencuri]

If I copy original videos back to the camcorder, it plays them, unlike other camcorder, that are unable to to that simple thing as well. So let us hope yet it can work. I try to make the final mp4 the same, if it fails I accept.

I can also see the reference frame is 2 in the original, and 1 in the final mp4. Can this also be a problem?

[Baldrick]

If I copy original videos back to the camcorder, it plays them, unlike other camcorder, that are unable to to that simple thing as well. So let us hope yet it can work. I try to make the final mp4 the same, if it fails I accept.

I can also see the reference frame is 2 in the original, and 1 in the final mp4. Can this also be a problem?

Okey. Then it might work.

Maybe try another converter also like a x264 frontend like tx264, vidcoder, etc. But then it could be the mp4 muxing also...mp4box or mp4muxer.

[Bencuri]

I will try those, but I have already tried several softwares, so first I would stick to Xilisoft, because I can set several things in it. If it doesn't work, I go on to those you suggested. I try to set the GOP now. Mediainfo writes M=2, N=30, is this what I should write to GOP in Xilisoft, or the two value must be written to 2 different places? In Xilisoft there is only a line: GOP, no other.

[Bencuri]

If I write M=2, N=30, that doesn't work, the output will be 1 and 12, what causes the problem?

[Bencuri]

So I am still unsure about how to get this M=2 N=30 Gop Setting, I found the reference frame setting. If I copy the output files back to the camcorder, it can see them, but marks them with a "?" mark. My JVC camcorder doesn't even see the videos that I copy back to the camcorder, so maybe there is still hope. About the header: If I record something with my Sanyo HD1000, the Sanyo FH1 can see that on the SD card and can play the file. So maybe there would be hope that this back conversion might work. I am not an expert, I only see that the JVC doesn't even recognise its original files when I copy them back to the AVCHD STREAM folder.

[turk690]

So my camcorder records in mp4. I stabilised the recorded videos in Mercalli, then I converted the output file back to mp4. I want to play this final video on my camcorder by connecting it to the TV. The problem is that this final mp4 cannot be played on the camcorder, it doesn't recognise the video. I used Xilisoft converter to make this file, I tried to set everything like the original, but it seems there is still something missing. Could you check the original and final mp4 and suggest what is still the problematic difference between the two file?

I have owned a number of tapeless camcorders. All of them can be connected via USB to a computer, and contents (recorded) of their internal media can be seen as an external drive in Windows. It is tempting to assume they then can be just like any other drive where we can put in and delete files from willy-nilly, and also expect the camcorder to play these. My experience has been mixed, even tending to disaster (a camcorder hard drive formatted in Windows couldn't be seen by the camcorder anymore). All such camcorder instruction manuals strongly emphasize that there is no guarantee files deliberately put in there will be played properly or at all. Typical *.mp4 files or other *.mts or *.mt2s files sourced from elsewhere that play perfectly fine on the computer almost NEVER behave the same from the camcorder hard drive. There is a lot of dynamic going on in the AVCHD file structure inside a camcorder's hard drive when recording or playing. These are never obvious to us mere mortal camcorder users. The contents of the other folders apart from the \STREAM folder are especially important: they will ultimately determine if any of the clips will be played. Or not. I consider the fact that the AVCHD camcorder can play back its own files a mere token. Gone are the glory days of DV where a high mark of a camcorder was to accept external (analogue) inputs and/or play back tapes made by other camcorders. These days, (and unfortunately more complex), my computer and blu-ray player form the record-playback loop of the system together with the camcorder. I'm acutely aware that if i take out a file from the camcorder and edit it, the ONLY way to play it back is through the computer. Failing that, I author a blu-ray disc with the same edited file if it MUST be viewed by many, and on a TV.

[Bencuri]

Well, I understand what you want to point out here, but this time I hope it can be different, as this Sanyo camcorder seems to be a bit more versatile than other camcorders. It makes only 1 folder, where it puts the file, so there is no complicated folder system with additional info files or what. It just creates a DCIM folder, inside a SANY100 folder, and put the files there. Files that were copied out earlier can be copied back any time later, and the device plays them, it also plays the files of my other Sanyo camcoder, when I copy that to the SANY100 folder. And that is a different type of device, not the same. So I agree that there is much warning about what I want to do, but seeing that at least this camcorder manages to do these things above, maybe there is still hope that a backconverted file could be played. Maybe not. That wouldn't be a surprise simply because of the facts what you write. But who knows. Maybe there are some devices that are an exception. Fo example this camcorder can also stream video through USB when using it in webcam mode. That is something other camcorders cannot really do. So maybe it has abilities that I can benefit from this time...

[Bencuri]

I talked to a guy who managed to convert back his files to MTS that can be played on his Panasonic V700 camcorder. That camcorder has a different file system than mine, he used MultiAVCHD, so I guess I have to go a different way. He checked my files and told me the problem why my camcorder doesn't play the backconverted MP4 is that my camcorder files are MP4 V2, while the backconverted is MP4 V1.

What is this MP4 V2, and which software is capable of converting files to it? I didn't find too much info in Google.

[poisondeathray]

ffmbc can remux to mp42 ; it's just a type of MP4 container spec

M=number of b-frames (max)
N=GOP size (max)

With camcorder videos the GOP size , GOP structure and b-frames placement and number don't change (they are non adaptive, but fixed structure). eg. IPBBPBBPBB....

Bitrate is CBR (1pass ABR) for camcorder videos

Mediainfo is incorrect, the original video uses 1 b-frame (IBPBPBP...), also deblocking is disabled

Having fewer reference frames usually won't cause incompatiblity (but more could) . Going to lower specs rarely causes problems - it's going higher that causes problems

As mentioned above, audio needs to be 48Khz (just copy the audio from the original - no quality loss)




Try this 5 sec re-encoded sample to see if it plays

[Bencuri]

Thank you!

I tested it, it is still missing something, but it is already a step further. Now the camcorder recognises that it is a video, and plays it, but only the sound can be heard, the picture is black, only black screen can be seen.