PCM issue with VirtualDub

[TPP]

I'm trying to convert/compress a 2GB AVI file to a ~120MB h.264 MP4 file using Virtualdub. I've done it before about a month ago, but now when I try to do it I get this popup:


[Attachment 45802 - Click to enlarge]

After looking it up I understand that PCM is the audio codec the original AVI file is using, but I don't see an option to convert it to another type of audio, the only option being to use no audio compression whatsoever. Is there a way to convert the audio using a command in an AviSynth text file, or is there a software I should download that will allow VDub to process PCM audio?

[DB83]

As the message reads, PCM is not an audio codec supported for mp4. Only mp2 or aac are supported.

You have two options. Check the audio codecs available under the audio >> compression menu and select one of the above. I guess you have direct stream copy checked at present.

If you do not have either of these codecs installed you would have to install at least one to proceed.

Or, if you are only converting, use a different program such as avidemux which has the appropriate codecs within the program.

Avisynth will not help since it only processes the frames and you still need an external program such as vdub to process the script which gets you back to square one if you do not have the appropriate codecs.

[LigH.de]

The original VirtualDub by Avery Lee does not even support MP4 output on its own (except for external encoders/multiplexers), it can only create AVI. Do you mean VirtualDub2 (former VirtualDub FilterMod), or do you use output plugins? (With external encoders/multiplexers, this error wouldn't even pop up, I assume).

[Marsia Mariner]

As the message reads, PCM is not an audio codec supported for mp4. Only mp2 or aac are supported.

MP1, MP2, MP3, AAC, AC3, DCA (a.k.a. DTS "coherent acoustics"), ALAC, and MPEG-4 ALS.

Please stop spreading incomplete and outdated information.

[poisondeathray]

As the message reads, PCM is not an audio codec supported for mp4. Only mp2 or aac are supported.

MP1, MP2, MP3, AAC, AC3, DCA (a.k.a. DTS "coherent acoustics"), ALAC, and MPEG-4 ALS.

Please stop spreading incomplete and outdated information.

And PCM... It's supported in MP4.

For example, some Sony cameras record with PCM in MP4 (e.g the XDCAM 35 variant)

It's just that open source muxers don't support it

[pandy]

For example, some Sony cameras record with PCM in MP4 (e.g the XDCAM 35 variant)

It's just that open source muxers don't support it

https://forums.adobe.com/message/9510643#9510643

Sony simply don't care what standard says...

[poisondeathray]

For example, some Sony cameras record with PCM in MP4 (e.g the XDCAM 35 variant)

It's just that open source muxers don't support it

https://forums.adobe.com/message/9510643#9510643

Sony simply don't care what standard says...

It's registered under mp4ra ISO standard as a codec sample entry code. The fourcc is "twos". It's uncompressed 16bit PCM

[DB83]

As the message reads, PCM is not an audio codec supported for mp4. Only mp2 or aac are supported.

MP1, MP2, MP3, AAC, AC3, DCA (a.k.a. DTS "coherent acoustics"), ALAC, and MPEG-4 ALS.

Please stop spreading incomplete and outdated information.

If the info is outdated then I humbly apologise. Given in good faith from the info as reported in avidemux.

[TPP]

You have two options. Check the audio codecs available under the audio >> compression menu and select one of the above. I guess you have direct stream copy checked at present.

Ah, I did have it in direct stream copy mode. I switched it over to full processing mode and was able to access a different compression, which seems to have fixed the issue. Thanks! :)

The original VirtualDub by Avery Lee does not even support MP4 output on its own (except for external encoders/multiplexers), it can only create AVI. Do you mean VirtualDub2 (former VirtualDub FilterMod), or do you use output plugins? (With external encoders/multiplexers, this error wouldn't even pop up, I assume).

Yeah I meant VirtualDub2, sorry for not being more specific.

[pandy]

It's registered under mp4ra ISO standard as a codec sample entry code. The fourcc is "twos". It's uncompressed 16bit PCM

Can't find codecs (url not working and MP4ra page is horrible), also seem this is not so obvious https://trac.ffmpeg.org/ticket/3818

btw personally i find lack of support for PCM on MP4 as bizarre and difficult to explain... i don't like MP4 even more now.

[poisondeathray]

It's registered under mp4ra ISO standard as a codec sample entry code. The fourcc is "twos". It's uncompressed 16bit PCM

Can't find codecs (url not working and MP4ra page is horrible), also seem this is not so obvious https://trac.ffmpeg.org/ticket/3818

btw personally i find lack of support for PCM on MP4 as bizarre and difficult to explain... i don't like MP4 even more now.

https://cconcolato.github.io/mp4ra/codecs.html#

[pandy]

https://cconcolato.github.io/mp4ra/codecs.html#

Specified not by MPEG 4 but by MJPEG2000...
Found another specifier 'raw$20' but same situation as for 'twos' - part of ISO/IEC 15444 not ISO/IEC 14496.

[poisondeathray]

https://cconcolato.github.io/mp4ra/codecs.html#

Specified not by MPEG 4 but by MJPEG2000...
Found another specifier 'raw$20' but same situation as for 'twos' - part of ISO/IEC 15444 not ISO/IEC 14496.

I think it's because it was already specified earlier, but in later revisions all those subtypes now all fall under the umbrella of "ISO base media formats." The MP4v2 specification came out in 2003 , but it ended there as MPEG4 part 14. The ISO base media formats (MPEG4 part 12) continued on , with revisions in 2005,2008,2012,2015. If you recall, "AC3" audio was not originally part of the 2003 spec, and was incompatible. It was added later to the ISO base media format.

Basically , if something was already defined and specified, you should use and reference that one, that's why JPEG2000 is listed

"technically identical text is published as ISO/IEC 14496-12 for MPEG-4, and as ISO/IEC 15444-12 for JPEG 2000, and reference to this specification should be made accordingly. "

https://en.wikipedia.org/wiki/ISO_base_media_file_format

List of all registered extensions for ISO Base Media File Format is published on the official registration authority website, www.mp4ra.org. The registration authority for code-points (identifier values) in "MP4 Family" files is Apple Inc. and it is named in Annex D (informative) in MPEG-4 Part 12.[5] Codec designers should register the codes they invent, but the registration is not mandatory[25] and some of invented and used code-points are not registered.[26] When someone is creating a new specification derived from the ISO base media file format, all the existing specifications should be used both as examples and a source of definitions and technology. If an existing specification already covers how a particular media type is stored in the file format (e.g. MPEG-4 audio or video in MP4), that definition should be used and a new one should not be invented

This is the wayback machine from 2008, from the MPEG chair
https://web.archive.org/web/20080714101745/http://www.chiariglione.org/mpeg/technologi...4-ff/index.htm




So maybe that's they wiggle room Sony uses ? I haven't found anything officially in the ISO/IEC documents that say it EXcluded twos audio . Other companies mux it too - e.g. mainconcept

[pandy]

I fully agree with you but also i can't blame ffmpeg developers for considering this as gray zone... not entirely clear, lot of 'IF' and add to this paid standard...