Young Free
2009-May-30 02:38 UTC
[Speex-dev] something wrong with narrowband and ultra-wideband?
I downloaded speex-1.2beta3-win32 binaries, and used the speexenc.exe and speexdec to process the file male.wav download from http://speex.org/samples I used both the narrowband and ultra-wideband mode:>speexenc -n --quality 3 male.wav n3.spxEncoding 8000 Hz audio using narrowband mode (mono)>speexdec n3.spx n3.wavDecoding 8000 Hz audio using narrowband mode (mono) Encoded with Speex speex-1.2beta3>speexenc -u --quality 3 male.wav u3.spxWarning: Trying to encode in ultra-wideband (sub-band CELP) at 8000 Hz. I'll do it but I suggest you try narrowband instead Encoding 8000 Hz audio using ultra-wideband (sub-band CELP) mode (mono)>speexdec u3.spx u3.wavDecoding 8000 Hz audio using ultra-wideband (sub-band CELP) mode (mono) Encoded with Speex speex-1.2beta3 I believe the ultra-wideband mode would produce more compressed data and better voice quality than the narrowband mode. However, I noticed that the facts is contrary: the compressed file u3.spx is smaller than the n3.spx, and the quality of u3.wav are worse than n3.wav. The source file and output files are attached. Is there something wrong with them ? Could you help me explain this phenomenon? Regards, Fred Young -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20090530/caa032b8/attachment-0001.htm -------------- next part -------------- A non-text attachment was scrubbed... Name: n3.spx Type: application/octet-stream Size: 6552 bytes Desc: not available Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20090530/caa032b8/attachment-0002.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: n3.wav Type: audio/wav Size: 96044 bytes Desc: not available Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20090530/caa032b8/attachment-0003.bin -------------- next part -------------- A non-text attachment was scrubbed... Name: u3.wav Type: audio/wav Size: 96364 bytes Desc: not available Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20090530/caa032b8/attachment-0004.bin -------------- next part -------------- A non-text attachment was scrubbed... Name: u3.spx Type: application/octet-stream Size: 2484 bytes Desc: not available Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20090530/caa032b8/attachment-0003.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: male.wav Type: audio/wav Size: 96044 bytes Desc: not available Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20090530/caa032b8/attachment-0005.bin