LPCM / MS ACM

[rugbyguy9]

MakeMKV is is ripping blurays with wrong ID for audio.

before ripping it shows LPCM, but after the rip it shows up as MS ACM.

is there a hot fix?

[Woodstock]

http://www.makemkv.com/forum2/viewtopic.php?f=8&t=2530

[rugbyguy9]

http://www.makemkv.com/forum2/viewtopic.php?f=8&t=2530

This does not explain if it is fixed or not because there is no Raw profile.

Can someone shed some light on this issue

for clarity



Windows info pane showing MS ACM codec



MakeMKV showing LPCM codec

[Woodstock]

I processed two disk sets on Monday that used LPCM audio, and handbrake said the MKV files contained LPCM audio.

I question what Windows says about ANY media, personally.

Wikipedia says:

Audio Compression Manager (ACM) is a Windows multimedia framework that manages audio codecs (compressor/decompressors). ACM can also be considered an API specification. A codec must conform to the implicit ACM specification to work with Windows Multimedia. ACM files can be recognized by their filename extension .acm. ACM files also use RIFF-compatible filetypes such as WAV or AVI as a "wrapper" to store audio data encoded by any audio codec supported by ACM.

ACM is considered an outdated framework/API and Microsoft now encourages the use of at least DirectShow. However, unlike ACM and the related Video Compression Manager (VCM), DirectShow provides no means to encode files for end-users but requires developers to build end-to-end graphs for encoding content. ACM also does not support VBR audio streams; therefore newer codecs like MPEG-4 AAC, Ogg Vorbis, FLAC etc. cannot be supported through ACM if using variable bitrates. Though many sources state the contrary, Ogg Vorbis does work well with the ACM, e.g. when embedded in a RIFF-compatible file (such as a WAV or AVI file as mentioned earlier), provided the Ogg Vorbis stream is encoded at a constant bitrate.

Piecing together other sources, it seems Windows reports a LOT of codec as "MS ACM", because it uses its ACM to handle them.

[rugbyguy9]

I processed two disk sets on Monday that used LPCM audio, and handbrake said the MKV files contained LPCM audio.

I question what Windows says about ANY media, personally.

Wikipedia says:

Audio Compression Manager (ACM) is a Windows multimedia framework that manages audio codecs (compressor/decompressors). ACM can also be considered an API specification. A codec must conform to the implicit ACM specification to work with Windows Multimedia. ACM files can be recognized by their filename extension .acm. ACM files also use RIFF-compatible filetypes such as WAV or AVI as a "wrapper" to store audio data encoded by any audio codec supported by ACM.

ACM is considered an outdated framework/API and Microsoft now encourages the use of at least DirectShow. However, unlike ACM and the related Video Compression Manager (VCM), DirectShow provides no means to encode files for end-users but requires developers to build end-to-end graphs for encoding content. ACM also does not support VBR audio streams; therefore newer codecs like MPEG-4 AAC, Ogg Vorbis, FLAC etc. cannot be supported through ACM if using variable bitrates. Though many sources state the contrary, Ogg Vorbis does work well with the ACM, e.g. when embedded in a RIFF-compatible file (such as a WAV or AVI file as mentioned earlier), provided the Ogg Vorbis stream is encoded at a constant bitrate.

Piecing together other sources, it seems Windows reports a LOT of codec as "MS ACM", because it uses its ACM to handle them.

Hi thanks for the reply, but MKVtoolnix also shows MS ACM

[Woodstock]

Today, I got another Aniplex title with LPCM audio, so I decided to run some tests with 1.10.6 and other programs.

MakeMKV shows:



After ripping, VLC shows:



And handbrake 1.07 shows:



I do not have any programs that show the audio as "MS ACM", so I cannot duplicate what you're seeing. Sorry.

[Krawk]

http://www.makemkv.com/forum2/viewtopic.php?f=8&t=2530

Your link goes to a thread from 2011 in which mike says he would have fixed soon. I believe the issue might be related to a post I just made in the dvd errors section.

[angelgraves13]

I simply use eac3to to extract to WAV and encode to DTS-HD MA. LPCM isn't supported by a lot of players.