RE: 96kHz 24bit WAV playback

John,

Yes, that sounds like the correct approach:

1) Have wav file format (wvffplin.cpp) report a mime type
   of "audio/L24" and properly set other stream header parameters
2) Add RFC3190 support (this is the RFC which specifies audio/L24)
   to the PCM renderer. This would include:
     a) claiming "audio/L24" as a supported stream mime type
     b) properly translating the audio/L24 packets into IHXAudioStream::Write() calls

Eric

=======================================
Eric Hyche ([email protected])
Principal Engineer
RealNetworks, Inc.


>-----Original Message-----
>From: [email protected] [mailto:[email protected]]
>On Behalf Of John Stirling
>Sent: Monday, March 30, 2009 1:22 PM
>To: [email protected]
>Subject: Re: [Helix-client-dev] 96kHz 24bit WAV playback
>
>Taking a standard 16 bit 44.1khz .wav file I've hand edited to report 24
>bit 96khz -
>
>(.wav raw hex field)
>Bits/sample = 0x18 0x00
>SampleRate= 0x00 0x77 0x01 0x00
>ByteRate = 0x00 0xca 0x08 0x00
>
>If I edit wvffplin.cpp as follows it gets through to the renderer.
>
>I presume what I need to do is report audio/L24 from wvffplin.cpp and
>make audrend.cpp claim (and render) audio/L24. Does that sound correct ?
>
>
>(wvffplin.cpp)
>
>        ///////////////////////////////
>        // This wave file is raw PCM //
>        ///////////////////////////////
>
>        // Don't set any opaque data
>        HX_RELEASE(pHeaderBuf);
>
>        // Set appropriate mime type
>        if (nBitsPerSample == 8)
>        {
>            pMimeType = "audio/L8";
>        }
>        else if (nBitsPerSample == 16)
>        {
>            pMimeType = "audio/L16";
>
>            // Remember to make all data net-endian
>            m_bSwapSamples = TRUE;
>        }
>        else if (nBitsPerSample == 24) //XXX
>        {
>
>            pMimeType = "audio/L8";
>        }
>
>
>(audrend.cpp)
>const char* const CPCMAudioRenderer::m_ppszStreamMimeTypes[] = {
>"audio/L8", "audio/L16", "audio/x-pn-wav",
>"audio/PCMA","audio/pcma","audio/PCMU",NULL };
>
>
>
>John Stirling wrote:
>> Hi Greg,
>>
>> OK thanks. I don't really have time to dig too much into this either
>> at the moment unfortunately. I guess we just say no to this for now
>> unless our customer wants to investigate themselves..
>>
>> John.
>>
>>
>> Greg Wright wrote:
>>> John Stirling wrote:
>>>> Any chance we could get a comment from one of your experts on .wav
>>>> playback (Jon/Ken I presume) before we start digging into this any
>>>> more ?
>>>>
>>>
>>> John,
>>>
>>> I don't have time to dig too deep, but I downloaded the file
>>>
>>>    Test_File_2_0_STEREO_PCM.wav
>>>
>>> from http://www.itrax.com/Pages/HelpFAQs.php#1 (PCM 96/24 2.0 stereo)
>>>
>>>
>>> It won't play back in splay because of a failure in:
>>>
>>>     HX_RESULT CPCMAudioFormat::Init(IHXValues* pHeader)
>>>
>>>
>>> It does:
>>>
>>>       retVal = pHeader->GetPropertyCString("MimeType", pMimeTypeStr);
>>>
>>> then:
>>>
>>>            else if (!strcmp(pszMimeType, "audio/x-pn-wav"))
>>>             {
>>>                 m_ucMimeType = kMimeTypeAudioXPNWav;
>>>             }
>>>
>>> Finally:
>>>
>>>                 // Get the opaque data
>>>                 IHXBuffer* pBuffer = NULL;
>>>                 retVal = pHeader->GetPropertyBuffer("OpaqueData",
>>> pBuffer);
>>>                 if (SUCCEEDED(retVal))
>>>
>>>
>>> There appears to be no OpaqueData, it returns HXR_FAIL, and ends
>>> up returning that error back up the chain. It does that for 2
>>> renderers.
>>>
>>> Not sure if that is much of a clue or not.
>>>
>>> --greg.
>>>
>>>
>>>
>>>>
>>>> Eric Hyche wrote:
>>>>> Hard to tell when using PC RealPlayer as comparison. It
>>>>> uses DirectX to play back .wav files, and not Helix,
>>>>> the Windows RealPlayer might be able to play it back
>>>>> but Helix still might not.
>>>>>
>>>>> If the changes suggested below by Greg didn't work,
>>>>> then further investigation is needed to find out
>>>>> why.
>>>>>
>>>>> Eric
>>>>>
>>>>> =======================================
>>>>> Eric Hyche ([email protected])
>>>>> Principal Engineer
>>>>> RealNetworks, Inc.
>>>>>
>>>>>
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: [email protected]
>>>>>> [mailto:[email protected]]
>>>>>> On Behalf Of John Stirling
>>>>>> Sent: Tuesday, December 23, 2008 4:14 AM
>>>>>> To: [email protected]
>>>>>> Subject: Re: [Helix-client-dev] 96kHz 24bit WAV playback
>>>>>>
>>>>>> I heard a rumour that the PC real player now supports 24/96
>>>>>> playback ?
>>>>>>
>>>>>> If so, is it possible to port those changes to cayenne ?
>>>>>>
>>>>>> John
>>>>>>
>>>>>>
>>>>>> John Stirling wrote:
>>>>>>
>>>>>>> I added 96000 into that list but still can't play the file.
>>>>>>>
>>>>>>> Is there anything else easy to try ?
>>>>>>>
>>>>>>> John
>>>>>>>
>>>>>>>
>>>>>>> John Stirling wrote:
>>>>>>>
>>>>>>>> Thanks (I remember that list)
>>>>>>>>
>>>>>>>> re 24 bit -
>>>>>>>>
>>>>>>>> . if the audio device only supports 16 bit would you expect the
>>>>>>>> core/resampler to handle that ?
>>>>>>>> . if the audio device supports 24 bit would the core be able to
>>>>>>>> output in 24 bit ?
>>>>>>>>
>>>>>>>> John
>>>>>>>>
>>>>>>>>
>>>>>>>> Greg Wright wrote:
>>>>>>>>
>>>>>>>>> From hxaudses.cpp:
>>>>>>>>>
>>>>>>>>> const unsigned short z_anValidSampleRates[] = { 8000,
>>>>>>>>>                                                 11025,
>>>>>>>>>                                                 16000,
>>>>>>>>>                                                 22050,
>>>>>>>>>                                                 32000,
>>>>>>>>>                                                 44100,
>>>>>>>>>                                                 48000,
>>>>>>>>>                                                 49512
>>>>>>>>>                                               };
>>>>>>>>>
>>>>>>>>> You might need to expand that list at least.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --greg.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> John Stirling wrote:
>>>>>>>>>
>>>>>>>>>> I tried a sample track on RealPlayer10 on windows and it
>>>>>>>>>> didn't work.
>>>>>>>>>>
>>>>>>>>>> The same track could play ok via itunes, but not via WMP10.
>>>>>>>>>>
>>>>>>>>>> See:
>>>>>>>>>> http://www.itrax.com/Pages/HelpFAQs.php#1
>>>>>>>>>> for track we're trying to play
>>>>>>>>>>
>>>>>>>>>> John
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Eric Hyche wrote:
>>>>>>>>>>
>>>>>>>>>>> I was hoping someone else would answer, since
>>>>>>>>>>> I'm not 100% certain of my answer... :-)
>>>>>>>>>>>
>>>>>>>>>>> If you are talking about playing back a raw
>>>>>>>>>>> 96kHz 24-bit-per-sample .wav file, then I can't
>>>>>>>>>>> think of a reason that *wouldn't* work, assuming
>>>>>>>>>>> the audio device could be opened at 96kHz
>>>>>>>>>>> and 24bits. If it couldn't be, then it would
>>>>>>>>>>> have to go through a few other layers of the
>>>>>>>>>>> system (resampler, etc.) which I *believe* suport
>>>>>>>>>>> this format, but I'm not sure.
>>>>>>>>>>>
>>>>>>>>>>> Jon/Ken: do you know if this would work, or
>>>>>>>>>>> have you ever tried 96kHz/24-bit playback?
>>>>>>>>>>>
>>>>>>>>>>> Eric
>>>>>>>>>>>
>>>>>>>>>>> =============================================
>>>>>>>>>>> Eric Hyche ([email protected])
>>>>>>>>>>> Technical Lead
>>>>>>>>>>> RealNetworks, Inc.
>>>>>>>>>>>
>>>>>>>>>>>> -----Original Message-----
>>>>>>>>>>>> From: [email protected]
>>>>>>>>>>>> [mailto:[email protected]] On
>>>>>>>>>>>> Behalf Of
>>>>>>>>>>>> John Stirling
>>>>>>>>>>>> Sent: Friday, January 18, 2008 5:04 AM
>>>>>>>>>>>> To: [email protected]
>>>>>>>>>>>> Subject: Re: [Helix-client-dev] 96kHz 24bit WAV playback
>>>>>>>>>>>>
>>>>>>>>>>>> Any response on this ?
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> John Stirling wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>> Is 96khz, 24bit WAV supported on cayenne1_5_0 ?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Seems a bit excessive, but someone is asking..
>>>>>>>>>>>>>
>>>>>>>>>>>>> John
>>>>>>>>>>>>>
>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>> Helix-client-dev mailing list
>>>>>>>>>>>>> [email protected]
>>>>>>>>>>>>> http://lists.helixcommunity.org/mailman/listinfo/helix-client-dev
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
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>>>>>>>>>>>> Helix-client-dev mailing list
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>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
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>>>>>>>>>>
>>>>>>>>>>
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