How to check if my MP4s have glitches, without playing them all back?

[Neil-Betamax]

I recently ripped all of my DVDs to MP4.

I'd like to know if its possible to discover which MP4s have glitches in without playing them all back individually?

I've seen that it could be possible ffmpeg, but Im struggling to understand ffmpeg enough to use it for this purpose and wonder if there's a different way.

The idea is to have a pile of DVDs of which I can be sure, ripped 100% successfully to MP4. Then I can capture the DVDs which have glitches by playing them from the DVD Player in realtime, into a black magic shuttle.

I've installed mediainfo and currently looking into whether this can work for the task at hand here, although I'm unsure if I'm looking in the right direction.

Any ideas would be great. Thanks!

[johns0]

Unless you know first hand there are glitches there's no real easy way to spot any if there at all,any reason you think there are glitches?

[Neil-Betamax]

Thanks Johns0,

I have a pile of DVDs I've ripped using Wonderfox, most of what I've played back as MP4s through VLC have turned out ok having watched from start to end.

There are some though, which are terribly garbled/digitally distorted in places.
I don't think the DVDs in question would play back or skip at these points (perhaps due to damage to the disk surface). I could test for that but as far as I can imagine, something has caused a glitch during the process of ripping the DVD.
The software can be a bit temperamental at times, so there's chance I could acheive a better result if I retried ripping the failed DVDs.
Its just knowing whether each rip has been succesful

[davexnet]

How are these mp4's created? How did you rip DVD > mp4?

[netmask56]

Much prefer ripping to MKV using MakeMKV and then running the MKV through MKVToolNix which lists any errors etc, also MKV container is easier to add or remove tracks.

[wiseant]

You could try this bat file that uses ffmpeg to check a folder of mp4's for errors

ECHO ON
if not exist error-check\ md error-check
for %%a in ("*.mp4") do "c:\ffmpeg\bin\ffmpeg" -v error -i "%%a" -f null - > "error-check/%%a.error.txt" 2>&1
pause

you just need to edit "c:\ffmpeg\bin\ffmpeg" if your ffmpeg.exe is elsewhere and save the batch file in notepad as error-check.bat then drag and drop the folder onto the batch file

this will create an error-check folder and all the error.txt files will have the filename as a prefix and will will be inside this folder

any file with more than 0 kb will have errors

e.g. I had a mp4 file that had errors - the mymp4file,error.txt file showed
[h264 @ 000001acac2f1520] error while decoding MB 3 0, bytestream -22
[h264 @ 000001acac2f19a0] top block unavailable for requested intra mode at 4 0
[h264 @ 000001acac2f19a0] error while decoding MB 4 0, bytestream 2

[davexnet]

e.g. I had a mp4 file that had errors - the mymp4file,error.txt file showed
[h264 @ 000001acac2f1520] error while decoding MB 3 0, bytestream -22
[h264 @ 000001acac2f19a0] top block unavailable for requested intra mode at 4 0
[h264 @ 000001acac2f19a0] error while decoding MB 4 0, bytestream 2

Aren't these kind of errors associated with files downloaded from the internet?

Is it likely you would get any errors with files you encoded on your own PC?

If these are protected, commercial DVD's you also have to consider the copy protection with the encrypted data
that the ripper supposedly fixes before it copies it to the HDD/SSD. But if some gibberish data got through
and then you created your mp4, the mp4 would probably encode and test normally, since it's own integrity would be intact,
regardless of whether the source was good/damaged

[lingyi]

I recently ripped all of my DVDs to MP4.

Being pedantic.

You didn't "rip" to MP4. You Ripped to MPEG-2, then either remuxed to the MP4 container or you reencoded your MPEG-2 to MPEG-4 Part 14, which includes the H.264 and H.265 video formats. If you did the latter, you've increased the possibility of compression errors as well as reduced the quality.

You stated you're using WonderFox. This is almost certainly ripping and reencoding. Stop. Use MakeMKV and either rip and remux to .MKV (container) or rip to an ISO or DVD folder/file structure.

Then I can capture the DVDs which have glitches by playing them from the DVD Player in realtime, into a black magic shuttle.

Utterly ridiculous. If the disks have glitches, they're likely due to physical damage to the disk, which a good resurfacing may repair or authoring errors. If the latter, check the disk with ISOBuster. I believe the free version will show if there are any errors reading the disk. You need the paid version to actually make a copy of the disk contents.

[wiseant]

@davexnet

Yes - that is a file I downloaded from the BBC - but wouldn't that batch check for errors for non-downloaded errors?

[davexnet]

@davexnet

Yes - that is a file I downloaded from the BBC - but wouldn't that batch check for errors for non-downloaded errors?

Yes it would, but in the scenario I pointed out, it's possible to still have a visible glitch and yet nothing would be detected -
kind of a false positive

[Neil-Betamax]

I recently ripped all of my DVDs to MP4.

Being pedantic.

You didn't "rip" to MP4. You Ripped to MPEG-2, then either remuxed to the MP4 container or you reencoded your MPEG-2 to MPEG-4 Part 14, which includes the H.264 and H.265 video formats. If you did the latter, you've increased the possibility of compression errors as well as reduced the quality.

You stated you're using WonderFox. This is almost certainly ripping and reencoding. Stop. Use MakeMKV and either rip and remux to .MKV (container) or rip to an ISO or DVD folder/file structure.

Then I can capture the DVDs which have glitches by playing them from the DVD Player in realtime, into a black magic shuttle.

Utterly ridiculous. If the disks have glitches, they're likely due to physical damage to the disk, which a good resurfacing may repair or authoring errors. If the latter, check the disk with ISOBuster. I believe the free version will show if there are any errors reading the disk. You need the paid version to actually make a copy of the disk contents.

Hiya, yeah I guess I never articulated as well as I could there. In the program, you can select what the output file will be, so I chose MP4 (I'm unsure if it captures uncompressed first and then converts it to MP4, but that's what I've done here.)

I'm going to need to investigate further, but its a shame I've bought Wonderfox if it can't do what it says properly. I've downloaded MakeMKV trial so I'll see if I get better results. I'm going to look into it further and might contact the makers of Wonderfox to see if there's a solution. I might even ask for a refund if it turns out that not all DVDs can be ripped, as that's what its advertised to do (wish me luck if I do try that route haha).

The glitches aren't due to damage on the disk as far as I can see. They play perfectly in a DVD player from start to end, so its something within the ripping process causing it as I can gather. Playing it back in realtime is just a back up solution if it turns out I don't get a good result from trying to rip them again - but this is where I'm upto, I just need to identify which DVDs didn't rip properly.

[Neil-Betamax]

How are these mp4's created? How did you rip DVD > mp4?

I used Wonderfox. I select the output file type as MP4, but I'm unsure if it rips as uncompressed and later converts it to the file type of choice.
Within the software I tend to select 5.1 for audio, & check deinterlaced if necessary. Those are the only options I'm using.

Hardware wise its:
USB DVD drive called Alxum,
Laptop is an intel Core i7 8th gen Thinkpad.

[Neil-Betamax]

You could try this bat file that uses ffmpeg to check a folder of mp4's for errors

ECHO ON
if not exist error-check\ md error-check
for %%a in ("*.mp4") do "c:\ffmpeg\bin\ffmpeg" -v error -i "%%a" -f null - > "error-check/%%a.error.txt" 2>&1
pause

you just need to edit "c:\ffmpeg\bin\ffmpeg" if your ffmpeg.exe is elsewhere and save the batch file in notepad as error-check.bat then drag and drop the folder onto the batch file

this will create an error-check folder and all the error.txt files will have the filename as a prefix and will will be inside this folder

any file with more than 0 kb will have errors

e.g. I had a mp4 file that had errors - the mymp4file,error.txt file showed
[h264 @ 000001acac2f1520] error while decoding MB 3 0, bytestream -22
[h264 @ 000001acac2f19a0] top block unavailable for requested intra mode at 4 0
[h264 @ 000001acac2f19a0] error while decoding MB 4 0, bytestream 2

Thanks for the suggestion here. I would need to take some time and research ffmpeg before I could try it out. I downloaded it before I posted this following a suggestion about ffmpeg within the forum, but I realised I'd need to look into how the program works. I didn't realise its a command prompt program till I downloaded it, so I couldn't tell what was going on or how to install it. I'm willing to try but it'd be good to know if I'm looking in the right direction before I go down that route, or if its possible at all.

[Neil-Betamax]

Much prefer ripping to MKV using MakeMKV and then running the MKV through MKVToolNix which lists any errors etc, also MKV container is easier to add or remove tracks.

Thanks for that, MakeMKV is something I'm going to look into. First though I want to see if anything is possible in Wonderfox as I've already paid for it, so it'd be a shame to miss out if I can find a way to get it to work properly.

If you use MKVTookNix to check for errors, would it let you know at what time in the file the errors are? Or, are the errors listed clear enough to identify how much digital distortion there might be within the file?

[Neil-Betamax]

@davexnet

Yes - that is a file I downloaded from the BBC - but wouldn't that batch check for errors for non-downloaded errors?

Yes it would, but in the scenario I pointed out, it's possible to still have a visible glitch and yet nothing would be detected -
kind of a false positive

Do you think MKVToolNix would be able to scan the files for glitch errors? I suppose I'd need to convert everything again to MKV.
But otherwise, do you think that perhaps its just something which isn't possible to achieve at all?