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icomm
Beginner
148 Views

GSMAMR

We are trying to decode AMR from a (any) 3gp file using MP4 Demuxer. The problem is that the decoder delivers audio that sounds like gurgling/alien speak.

Are there any special transformations needed for this to work?

Thank you
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8 Replies
Sergey_O_Intel1
Employee
148 Views


No special requirements. Maybe the problem is in MP4 multiplexor? What decoder do you use? Anyway if you attach your 3gp file I can have a look at it. If it is played OK on some player it should be also played by simple_player (IPP sample).
icomm
Beginner
148 Views

Quoting - sergey_o

No special requirements. Maybe the problem is in MP4 multiplexor? What decoder do you use? Anyway if you attach your 3gp file I can have a look at it. If it is played OK on some player it should be also played by simple_player (IPP sample).

Thanks for replying.
We have tried multiple .3gp files, that contain AMR. Unfortunately non of them worked. We are not multiplexing them ourselves.
We are usingUSC_GSMAMR_Fxns to decode these audio frames.
In VLC it says "samr" and simple_player says that the format is not supported, but the MP4 Splitter returns AMR.

One if the files we used we got fromhttp://freemobilvideos.com/getfile.php?ID=608

Thanks
Vincent_Fournier
Beginner
148 Views

Quoting - icomm

Thanks for replying.
We have tried multiple .3gp files, that contain AMR. Unfortunately non of them worked. We are not multiplexing them ourselves.
We are usingUSC_GSMAMR_Fxns to decode these audio frames.
In VLC it says "samr" and simple_player says that the format is not supported, but the MP4 Splitter returns AMR.

One if the files we used we got fromhttp://freemobilvideos.com/getfile.php?ID=608

Thanks

Hi,
I just migrated to IPP 6.0 from an older version and now I seem to have the same problem as you (strange voice). It used to work well on IPP 4.1. Did you have any success with decoding GSMAMR? If so I would be greatful if you pointed me to the solution.
Thanks
Vincent_Fournier
Beginner
148 Views


I have isolated a bit more the problem. When I us the IPP 6.0 library and force it to use:
ippStaticInitCpu(ippCpuPP), I get good audio. My detected CPU is ippCpuEM64T (I have a Pentium D dual core processor) and I work under Windows XP 32bit. I have tried to isolate the function responsible for this by prefixing all the calls with px_ to force the call of the C optimized library, but that did notfix the problem. It seems that the problem comes from a hidenlow level function.

Vyacheslav_Baranniko
New Contributor II
148 Views


I have isolated a bit more the problem. When I us the IPP 6.0 library and force it to use:
ippStaticInitCpu(ippCpuPP), I get good audio. My detected CPU is ippCpuEM64T (I have a Pentium D dual core processor) and I work under Windows XP 32bit. I have tried to isolate the function responsible for this by prefixing all the calls with px_ to force the call of the C optimized library, but that did notfix the problem. It seems that the problem comes from a hidenlow level function.


Hello Vincent,

IPP team appreciates your effort in investigating the issue. It would be helpful you to try to start with working PX code (ippCpuPP) by perfixing IPP funcions with t7_ dispatching it to the code appropriate to ippCpuEM64T. Starting with the working code you willdefinitely identify the suspicious function.

Thank you,
Vyacheslav, IPP, speech coding domain
icomm
Beginner
148 Views


I have isolated a bit more the problem. When I us the IPP 6.0 library and force it to use:
ippStaticInitCpu(ippCpuPP), I get good audio. My detected CPU is ippCpuEM64T (I have a Pentium D dual core processor) and I work under Windows XP 32bit. I have tried to isolate the function responsible for this by prefixing all the calls with px_ to force the call of the C optimized library, but that did notfix the problem. It seems that the problem comes from a hidenlow level function.


We rewrote the bitstream unpacker for the storage format and pass that directly to the decoder. Everything works fine now. Take a look at the 26073-800 reference impl at 3gpp.

Tom
Vyacheslav_Baranniko
New Contributor II
148 Views


I have isolated a bit more the problem. When I us the IPP 6.0 library and force it to use:
ippStaticInitCpu(ippCpuPP), I get good audio. My detected CPU is ippCpuEM64T (I have a Pentium D dual core processor) and I work under Windows XP 32bit. I have tried to isolate the function responsible for this by prefixing all the calls with px_ to force the call of the C optimized library, but that did notfix the problem. It seems that the problem comes from a hidenlow level function.


Vincent, it wouldbe more productive if youpost this issue thru premier.intel.com. This will require IPP registration.
Vyacheslav
Vincent_Fournier
Beginner
148 Views

Quoting - vbaranni

Hello Vincent,

IPP team appreciates your effort in investigating the issue. It would be helpful you to try to start with working PX code (ippCpuPP) by perfixing IPP funcions with t7_ dispatching it to the code appropriate to ippCpuEM64T. Starting with the working code you willdefinitely identify the suspicious function.

Thank you,
Vyacheslav, IPP, speech coding domain

I have been on a differentproject and just read your suggestion. It is a good idea. I'll try it as soon as I have the opportunity. I will also report my findings to the premium support channel as you suggest in a latter message (I am already a registered user).

Thank you,
Vincent
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