I have an MPEG-2 Mezzanine file that crashes DGIndex 1.5.7!

[Blue_MiSfit]

Hi folks (neuron2)

I have a studio MPEG-PS mezzanine file containing high bitrate CBR 1080p MPEG-2 and AC3 audio. It crashes DGIndex! Nasty!

Here's a 100MB sample that I can reliably reproduce the issue with:

*uploading now*

The same file plays perfectly fine in VLC or MPC-HC using the internal MPG splitter and ffdshow's libavcodec MPEG-2 decoder.

I can also use this DirectShow chain to transcode the file using DSS2 in AviSynth.

ffms2's ffmsindex does crash when trying to index the file, and eac3to doesn't see the audio track. I can however extract the audio using DGIndex :)

What a curious little problem. Hopefully neuron2 can fix things in DGIndex for me!

[Guest]

Post again when the upload is done so I don't forget your thread.

And when you do, please advise what a "mezzanine file" is.

[Blue_MiSfit]

Hi neuron2,

A "mezzanine file" is simply a high quality captured file usually from a master tape, like a DigiBeta, HDCAM(-SR), or D5. My work brings me many types of mezzanine files, and MPEG PS with 50-80mbps MPEG-2 is a common one, as is MOV with ProRes and PCM.

Here's the link
http://www.mediafire.com/?mjdwltdqdrz

[Guest]

It's OK when demuxed so something is either wrong with the program stream itself or with my parsing thereof. Investigating...

Works fine in DGIndexNV, BTW.

[Blue_MiSfit]

Oh really? Interesting! Reminds me, I need to have you swap license files for me, since I had to add a second NIC to my work machine... I'll send you an e-mail.

As I'm sure you're aware, "professional" (emphasis on the quotes) encoders sometimes do very odd things. I'm hoping that by providing samples like these to folks like you and madshi, we can improve the capability of free software to demux files out there in the "professional" world.

Next, I need to start whining at someone to write an open-source ProRes decoder. This would quite possibly be the most useful thing ever! :)

Thanks for looking at the sample, neuron2!

~MiSfit

[Guest]

The problem is that the audio payload is AC3 but it is packetized as MPEG audio, i.e., the stream id is 00 00 01 c0.

That is therefore a pathological stream. I have fixed the crashing so that the video plays but there is nothing I can do to get audio out of it. The other programs I have also puke on that.

[Flaarn]

please forgive me for butting in here, this seems like a similar problem we suffered with bbc hd transport streams for a while, this was fixed by patching the startcodes, I know your source is different but maybe a similar method could be applied.
http://www.dvbviewer.info/forum/index.php?showtopic=18449

[Guest]

Thanks for the interesting info, Flaarn. I thought of patching the codes but my freeware Neo hex editor needs the paid version to do global search and replace. :( And I don't have the time to write a custom tool for it.

[kypec]

Ever heard of XVI32 hex editor (http://www.chmaas.handshake.de/delphi/freeware/xvi32/xvi32.htm)? It has nice scripting abilities to do search & replace on large files. Just a thought.

[Blue_MiSfit]

Thanks for the info, neuron2! I will communicate this back to the creator of this nasty little bugger and see if they can resolve it on their end.

The audio and video do play perfectly in MPC-HC, so there must be some kind of workaround happening there, correct?

~MiSfit

[Guest]

The audio and video do play perfectly in MPC-HC Didn't work for me.

[Blue_MiSfit]

My mistake. I was confused. I had played an H.264 TS that I had transcoded from this source, with audio from an elementary AC3 that was delivered separately to work around this issue.

Thank you again for taking the time to look at this. Do you plan to release a build that can successfully index the MPG (with the audio issue aside)? If not, no big deal. I'll be coordinating with this encoding house to deliver something more logical in the future.

~MiSfit

[Guest]

Do you plan to release a build that can successfully index the MPG I can do it for you this weekend. Wilbert wants the latest source code so I'll make a full source release 1.5.8 with this fix.

[Blue_MiSfit]

Thank you, kind sir! I will certainly monitor this thread for an update, and drop it into our workflow ASAP.

~MiSfit

[Guest]

Version 1.5.8 with source code is now available at my web site.