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tlytle
09-01-2004, 08:28 AM
Please help me clear up some confusion over audio quality. I am extracting audio tracks (Freeview, etc) from my DTivo using the tytools vsplit option with no transcoding. My understanding is that the dtivo uses a frequency of 48kHz with a sampling rate of 192 bps for recording audio and this should be very near CD/DVD audio quality. Using an audio converter, I convert the MP2 dtivo file into a wav file (44.1kHz, stereo, 16 bit) and burn on a CD. The quality of the audio is noticebly less than audio CD.

Questions
1 - Do I have unrealistic expectations?
2 - Is the quality of the dtivo audio stream significantly lower than CD audio?
3 - Is the quality of the incoming broadcast stream significantly lower than CD audio and thats where the problem is?

eastwind
09-01-2004, 11:23 AM
Please help me clear up some confusion over audio quality. I am extracting audio tracks (Freeview, etc) from my DTivo using the tytools vsplit option with no transcoding. My understanding is that the dtivo uses a frequency of 48kHz with a sampling rate of 192 bps for recording audio and this should be very near CD/DVD audio quality. Using an audio converter, I convert the MP2 dtivo file into a wav file (44.1kHz, stereo, 16 bit) and burn on a CD. The quality of the audio is noticebly less than audio CD.

Questions
1 - Do I have unrealistic expectations?
2 - Is the quality of the dtivo audio stream significantly lower than CD audio?
3 - Is the quality of the incoming broadcast stream significantly lower than CD audio and thats where the problem is?
Any time you transcode you will lower the quality. Upsampling adds interpreted or blank data bits. Downsampling removes data. Either way you lose some quality (I think that's correct, anyway). DTV audio (what DTiVo records) is compressed audio and has already lost some quality from the original (MPEG-1 Layer 2 is a lossy compression). So I believe the answer to all three questions is yes!

ew