Rockbox Development > Feature Ideas
[Feature Suggestion] Recording to WMA or some other format.
dangerousd777:
--- Quote from: saratoga on February 02, 2009, 10:34:21 PM ---
--- Quote from: dangerousd777 on February 02, 2009, 10:08:06 PM ---It would be interesting if it was easy to add your own codecs to Rockbox for testing purposes, I'm sure there's ways but I'm not much of a software developer/tester, or programmer or anything else.
--- End quote ---
Its not that difficult compared to actually writing them.
--- Quote from: dangerousd777 on February 02, 2009, 10:08:06 PM ---Even Vorbis is less CPU intensive than WMA according to that chart,
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Which chart?
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Writing them would surely be difficult. What does it take to add a codec to Rockbox?
There may not be a fixed point encoder but there are just various encoders some of which are open-source such as LibravCodec, FFMpeg and MEncoder.
In http://www.hydrogenaudio.org/forums/lofiversion/index.php/t48790.html user HotShotGG says "Not yet, [there is no fixed Ogg Vorbis encoder that I know of.] It is possible just by looking at the code. It can be done."
In http://www.hydrogenaudio.org/forums/lofiversion/index.php/t48898.html user Gabriel states "This encoder is small enough to be converted to fixed point. If going this way, it would be a huge progress for Vorbis, and a quite interesting thing."
The Codec Performance Comparison chart in the Rockbox TWiki that you posted the link to, I took a quick glance at the Sansa e260s stats and even Ogg Vorbis beats out WMA.
If someone COULD create a fixed point encoder somehow for Rockbox, it would be superb. It would save plenty of space and would be higher quality than Mp3 when recording from Mic or FM radio.
It seems plausible, but perhaps too difficult. The encoding differences, well then I'm not sure unless I could test out my Sansa for those kind of things, but I can't access the Debug menu to View buffering thread (To see CPU usage and such) while recording, or maybe I can but I'm just not aware of the method yet.
I'd like to see either WMA or Ogg Vorbis implemented, but if not then I'll have to deal with Mp3.
AlexP:
decoding speed != encoding speed
Yes, converting to fixed point is a very big job. I doubt many people would bother as you can already either record to MP3, or record to wavpack (lossless) then compress later. Still if someone did, it would of course be welcomed.
--- Quote from: dangerousd777 on February 04, 2009, 12:10:40 AM ---I'd like to see either WMA or Ogg Vorbis implemented, but if not then I'll have to deal with Mp3.
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Best get coding then!
saratoga:
--- Quote from: dangerousd777 on February 04, 2009, 12:10:40 AM ---The Codec Performance Comparison chart in the Rockbox TWiki that you posted the link to, I took a quick glance at the Sansa e260s stats and even Ogg Vorbis beats out WMA.
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Testing WMA now, I get about 265% real time on the Sansa. Looking at that page, the only numbers for WMA are from 18 months ago right after I added it to Rockbox.
dangerousd777:
--- Quote from: saratoga on February 04, 2009, 09:24:25 AM ---
--- Quote from: dangerousd777 on February 04, 2009, 12:10:40 AM ---The Codec Performance Comparison chart in the Rockbox TWiki that you posted the link to, I took a quick glance at the Sansa e260s stats and even Ogg Vorbis beats out WMA.
--- End quote ---
Testing WMA now, I get about 265% real time on the Sansa. Looking at that page, the only numbers for WMA are from 18 months ago right after I added it to Rockbox.
--- End quote ---
Damn that's pretty fast. I've noticed that there have been huge improvements to the decoders over time for different ports. How well do Mp3 and Vorbis decode now in the later/latest version(s)?
--- Quote from: BigBambi on February 04, 2009, 04:17:44 AM ---decoding speed != encoding speed
Yes, converting to fixed point is a very big job. I doubt many people would bother as you can already either record to MP3, or record to wavpack (lossless) then compress later. Still if someone did, it would of course be welcomed.
--- Quote from: dangerousd777 on February 04, 2009, 12:10:40 AM ---I'd like to see either WMA or Ogg Vorbis implemented, but if not then I'll have to deal with Mp3.
--- End quote ---
Best get coding then!
--- End quote ---
So is encoding speed is similar to decoding speed? Or is one a bit more than the other.
I don't think there are fixed-point encoders for WMA and Ogg Vorbis, but my friend Lainlives may know of something or may be able to code them... that is if he has interest in it. He has Rockbox on his PSP so he might have some interest. :P
While most people would just encode them on PC, if you have them already encoded in Rockbox they're perfectly prepared, and you could record for much longer at lower bitrates without seeming to lose quality (Ogg Vorbis has an excellent psychoacoustic model.)
I think from the Sansa e200 microphone that Lossless WAV and Lossless/Lossy hybrid such as WAVPack aren't that necessary. I mean your only encoding to monaural and at 22,050 samples per second (I never really understood why it's only monaural and not stereophonic and the sampling frequency is limited to ONLY 22,050 but nothing lower and nothing higher. Maybe it has something to do with hardware limitations ???)
For that Mp3 128-144 to even 160 should be good enough.
Note: I figure I could always resample the sample frequency, encode to whichever format of my preference and change from mono to stereo. I'm still interested in this subject however, much more feasible than the video formats, seeing as those would be restricted by hardware limitations such as available computational power of the Sansa e200.
evilnick:
--- Quote ---Note: I figure I could always resample the sample frequency, encode to whichever format of my preference and change from mono to stereo. I'm still interested in this subject however, much more feasible than the video formats, seeing as those would be restricted by hardware limitations such as available computational power of the Sansa e200.
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You could, but this wouldn't magically make the sound any higher fidelity, it'd be exactly the same but take up more filesize.
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