Encoders & CD audio tools

MP3 is still one of the most widely supported compressed audio formats. The supplied LAME 4.0 cVBRb builds are intended for users who want MP3 compatibility while retaining more control over the lower end of a variable-bitrate encode. Performance is the normal choice for modern systems; Solid State is the compatibility-focused alternative.

The supplied cVBRb builds extend the normal LAME 4.0 feature set rather than replacing it. Standard LAME CBR, ABR and VBR operation remains available, while cVBRb adds stricter lower-bitrate control to the constrained-VBR path.

For MP3, fixed CBR rates use the normal Layer III bitrate set, while ABR chooses an average target and VBR is quality-driven through the usual -V scale. The EAC preset shown here uses -V0 together with a strict 192 kbps minimum and bitrate boost.

Because cVBRb is an extension of standard LAME 4.0, the site describes its additional controls separately from LAME's established CBR/ABR/VBR behaviour.

FLAC compresses PCM audio without discarding audio information. Decoding returns the lossless audio, making FLAC well suited to CD archiving and general high-quality playback. Unlike a lossy codec, FLAC does not use a target audio bitrate to determine quality.

Compression level changes encoding effort and resulting file size rather than decoded audio quality. The verified EAC command on this site uses level 5.

AAC is a modern perceptual codec commonly carried in an M4A/MP4 container. It is useful where broad modern-device support and efficient lossy compression are more important than MP3's near-universal legacy compatibility.

CW-AAC expects the input and output as its first two positional arguments. The recommended EAC setup therefore keeps %source% %dest% at the start of the command line.

ALAC is a lossless codec stored in an M4A container. It is particularly useful when lossless storage is required alongside strong compatibility with Apple software and devices.

There is no lossy quality or bitrate mode to select: output bitrate varies with the source audio while preserving lossless reconstruction.

Opus is a modern, high-efficiency lossy codec with strong software playback support. CW-Opus automatically resamples input when required for an Opus-compatible sample rate.

VBR is the normal/default Opus operating mode. -cvbr by itself selects standard constrained VBR, while -cvbr together with an explicit -b value enables CW protective cVBR, where the requested bitrate acts as a minimum for eligible CELT frames. -cbr selects constant bitrate.

The default requested bitrate is 128 kbps. The EAC guide deliberately uses -cvbr -b 256000 --complexity 10, giving a 256 kbps protective-cVBR configuration with maximum encoder complexity.

44.1 kHz input is automatically resampled to 48 kHz by the CW 64-tap Blackman-windowed sinc frontend. Native Opus API sample rates bypass that resampler.

AC-3 is a lossy multichannel format commonly associated with Dolby Digital playback. For the EAC workflow, standard 44.1 kHz CD PCM is automatically resampled to 48 kHz before AC-3 encoding.

CW-AC3 produces 48 kHz AC-3 using constant bitrate encoding at all 19 legal AC-3 bitrates from 32 through 640 kbps. In the normal CD workflow, 44.1 kHz EAC input is therefore converted to 48 kHz automatically.

The encoder also provides matrix-stereo decoding with a 20 ms default rear delay (adjustable from 0–40 ms), and a --thx preset that enables fixed 80 Hz LR4 bass management.

DTS Core is a lossy multichannel format used by a wide range of home-cinema and optical-disc playback systems. CW-DTS is especially relevant to EAC because it supports native 44.1 kHz CD-rate PCM rather than forcing the EAC source to 48 kHz.

CW-DTS exposes four constrained DTS Core bitrate profiles: 768, 1024, 1152 and 1411.2 kbps. The command-line syntax uses 1411 for the highest profile, mapping exactly to 1,411,200 bit/s.

Public input support covers 44.1 and 48 kHz PCM, including native CD-rate 44.1 kHz operation. The encoder supports stereo and validated 3.0, 4.0, 5.0 and 5.1 layouts. Optional matrix processing shares the CW-AC3 steering behaviour, including a 20 ms default rear delay and the --thx 80 Hz LR4 bass-management preset.

DTS-CD places a compressed DTS bitstream inside audio-CD sample words. A rip can therefore look like ordinary 44.1 kHz, 16-bit stereo PCM even though the payload contains DTS data. The carrier must remain bit-perfect.

Raw .dts output is a bitstream extraction rather than a decode/re-encode operation. FLAC output is decoded lossless PCM and preserves the channel layout reported by the DTS decoder.

CW-HDCD detects and reconstructs supported HDCD signalling carried in stereo PCM audio. Normal decoding produces 24-bit PCM without resampling, normalisation, ReplayGain, additional DSP or dithering.

Preserve-HDCD performs lossless PCM16 container conversion without reconstructing the HDCD signal, preserving the original PCM sample values and embedded signalling unchanged.