Recording on iRiver

Features

• 16 bit stereo and mono recording
• 44.1, 22.05 and 11.025 kHz sampling rates
• Uncompressed WAV and AIFF format
• Compressed WavPack format
• Real-Time MP3 encoding at various bitrates (quality)
• Recording via Optical In (spdif)
• Peak meter (before and during recording)
• Automatic gain control (AGC)
• Records almost 3 minutes before saving to disk (when recording to mp3, even more depending on the compression selected)
• Seamless time or size split (start a new file when specified time or file size is reached)
• Seamless auto-split at max. file size (2GB - 1MB ~= 3h 23m (uncompressed))
• Prerecording (configurable, up to 30 seconds)
• Triggered recording

Missing features

• Set a start or stop time (delayed/timed recording)

Needs more testing

• Stop while flushing to disk should work now
• Recording uses cpu_boost now, otherwise the backlight fading (which changes cpu_boost) causes DMA to fail.

Gain settings

For both Mic and Line-in there is an analog and digital gain setting. Because the steps of the decimator are much smaller, they are used to add additional gain values between the (big) analog steps. So the gain will always change in 0.5dB steps, and be the optimal combination of analog and digital gain. For the purists, an indicator behind the gain value shows if the decimator is used.

Line-in and internal mic gain are stored separately in the configuration.

In the recording screen, with volume selected, pressing down first selects both left and right gain for stereo change. Pressing down again will then first select left gain, then right gain.

Setting	Affects	Description	Range
Mic gain	Internal mic	Analog gain for microphone LNA (Low Noise Amplifier)	0 dB to 30 dB (2dB steps)
Line-in gain	Line-in (and external mic)	Analog gain for line-in PGA (Programmable Gain Amplifier)	0 dB to 24 dB (3dB steps)
Decimator gain	Both mic and line-In	Digital decimator volume	-63 dB to 24 dB (0.5dB steps)