help: problem with decoding mp3 in AVR with sample rates other than 48khz

jayad08

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Jul 18, 2009
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Hi,
I recently configred the SPDIF/optical part with my AVR.
I am able to pass through AC3/DTS with ease.
The problem comes when I play MP3s. I have intentionally setup AC3Filter as mp3 decoder and let it convert MP3s to AC3 on the fly..
I am able to play mp3s with sample rate of 48khz fine(the Dolby Digital lights up in AVR), but I am not able to play others(normally you have 44.1khz sample rate in mp3s)
There are options of changing the sample rate in AC3Filter,but seems to me that these are not working..
I am attaching the screens for AC3Filter setting.. and the Filter chain dump for a 48khz song and 44.1khz converted to 48khz(not working) song

Will I have to sample all the songs to 48khz or there is some workaround available?

experts.. please help..

-----------------------------------------------------------
Song 1:
Input format: PCM16 2/0 (stereo) 48000
User format: PCM16 - 0
Output format: SPDIF 2/0 (stereo) 48000

Use SPDIF
SPDIF status: AC3 encode
SPDIF passthrough for: MPA AC3 DTS
Use AC3 encoder (encode stereo PCM)
Check SPDIF sample rate (allow: 48kHz 44.1kHz 32kHz)
Query for SPDIF output support

Decoding chain:
(PCM16 2/0 (stereo) 48000) -> Detector -> (PCM16 2/0 (stereo) 48000) -> Processor -> (Linear PCM 2/0 (stereo) 48000) -> Encoder -> (AC3 2/0 (stereo) 48000) -> Spdifer -> (SPDIF 2/0 (stereo) 48000) -> Dejitter -> (SPDIF 2/0 (stereo) 48000)

Filters info (in order of processing):

Detector:
-

Processor:
(PCM16 2/0 (stereo) 48000) -> PCM->Linear converter -> (Linear PCM 2/0 (stereo) 48000) -> Input levels -> (Linear PCM 2/0 (stereo) 48000) -> Input cache -> (Linear PCM 2/0 (stereo) 48000) -> SRC -> (Linear PCM 2/0 (stereo) 48000) -> Mixer -> (Linear PCM 2/0 (stereo) 48000) -> Bass redirection -> (Linear PCM 2/0 (stereo) 48000) -> Equalizer -> (Linear PCM 2/0 (stereo) 48000) -> Dither -> (Linear PCM 2/0 (stereo) 48000) -> AGC -> (Linear PCM 2/0 (stereo) 48000) -> Delay -> (Linear PCM 2/0 (stereo) 48000) -> Output cache -> (Linear PCM 2/0 (stereo) 48000) -> Output levels -> (Linear PCM 2/0 (stereo) 48000)

Encoder:
-

Spdifer:
Stream format: AC3 2/0 (stereo) 48000Hz
Bitstream type: byte stream
Frame size: 2560
Samples: 1536
Bitrate: 640kbps
SPDIF stream type: 0x1
Frame interval: 2560
Actual bitrate: 640kbps
Output format: SPDIF 2/0 (stereo) 48000Hz
SPDIF format: wrapped
Bitstream: 16bit LE
Frame size: 6144

Dejitter:
-

---------------------------------------------
Song 2:
Input format: PCM16 2/0 (stereo) 44100
User format: PCM16 - 48000
Output format: SPDIF 2/0 (stereo) 48000

Use SPDIF
SPDIF status: AC3 encode
SPDIF passthrough for: MPA AC3 DTS
Use AC3 encoder (encode stereo PCM)
Check SPDIF sample rate (allow: 48kHz 44.1kHz 32kHz)
Query for SPDIF output support

Decoding chain:
(PCM16 2/0 (stereo) 44100) -> Detector -> (PCM16 2/0 (stereo) 44100) -> Processor -> (Linear PCM 2/0 (stereo) 48000) -> Encoder -> (AC3 2/0 (stereo) 48000) -> Spdifer -> (SPDIF 2/0 (stereo) 48000) -> Dejitter -> (SPDIF 2/0 (stereo) 48000)

Filters info (in order of processing):

Detector:
-

Processor:
(PCM16 2/0 (stereo) 44100) -> PCM->Linear converter -> (Linear PCM 2/0 (stereo) 44100) -> Input levels -> (Linear PCM 2/0 (stereo) 44100) -> Input cache -> (Linear PCM 2/0 (stereo) 44100) -> SRC -> (Linear PCM 2/0 (stereo) 48000) -> Mixer -> (Linear PCM 2/0 (stereo) 48000) -> Bass redirection -> (Linear PCM 2/0 (stereo) 48000) -> Equalizer -> (Linear PCM 2/0 (stereo) 48000) -> Dither -> (Linear PCM 2/0 (stereo) 48000) -> AGC -> (Linear PCM 2/0 (stereo) 48000) -> Delay -> (Linear PCM 2/0 (stereo) 48000) -> Output cache -> (Linear PCM 2/0 (stereo) 48000) -> Output levels -> (Linear PCM 2/0 (stereo) 48000)

Encoder:
-

Spdifer:
Stream format: AC3 2/0 (stereo) 48000Hz
Bitstream type: byte stream
Frame size: 2560
Samples: 1536
Bitrate: 640kbps
SPDIF stream type: 0x1
Frame interval: 2560
Actual bitrate: 640kbps
Output format: SPDIF 2/0 (stereo) 48000Hz
SPDIF format: wrapped
Bitstream: 16bit LE
Frame size: 6144

Dejitter:
-

-------------------------------------------------------------
 
Last edited:
AC-3 supports audio sample-rates up to 48 kHz. More than that, your receiver will probably reject it. Most probably 2 channel mp3 will be fine at higher rates, but ac3 doesnt support it.
 
problem resolved!!
silly really.. it was a problem of the player rather than AC3Filter..
I used windows media player - no filter chain issues.. worked just fine..
no problems with 44.1khz now..
 
problem resolved!!
silly really.. it was a problem of the player rather than AC3Filter..
I used windows media player - no filter chain issues.. worked just fine..
no problems with 44.1khz now..

Download VLC player...and all problem like above will be sorted out. A real good streamer as well....Its freeware.
quote
"VLC media player is a highly portable multimedia player and multimedia framework capable of reading most audio and video formats (MPEG-2, MPEG-4, H.264, DivX, MPEG-1, mp3, ogg, aac ...) as well as DVDs, Audio CDs VCDs, and various streaming protocols.
Unquote
VLC media player - Open Source Multimedia Framework and Player
:licklips:Enjoy
 
i have VLC, also saw the option "Use SPDIF if available" tried to use it, but couldn't get digital stream out from optical.. so tried AC3Filter..
Thanks anyways..
 
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