与从音频编码类似，从 CD 编码是一个两阶段的过程。首先，从 CD 中提取音频数据并转换为 wav 文件。然后，wav 文件被转换为 MP3。
基本上有两种类型的编码器，基于控制台的和基于 X 窗口系统的。两者都做同样的工作，但是基于 X 窗口系统的编码器更容易使用（并且看起来更漂亮）。
同样，在开始编码之前，请检查您的系统是否有足够的驱动器空间。
我编写了一个非常简单的 Perl 脚本，可以从 CD 中抓取和编码音轨。
#!/usr/bin/perl
if ($ARGV[0] ne "") {
$count = 1;
do {
$cdcap = system("cdparanoia", $count, "/mp3/cdda.wav");
$track = "$ARGV[1]/track".$count.".mp3";
$enc = system("bladeenc /mp3/cdda.wav $track -br 256000");
$count++;
}
until $count > $ARGV[0];
exit;
}
else {
print "Usage cdriper [no of tracks] [destination directory]\n\n";
}
主要的关注行是
$cdcap = system("cdparanoia", $count, "/mp3/cdda.wav");
此行调用 CD 抓取工具 cdparanoia。Cdparanoia 将原始 CD 音频数据转换为 WAV 格式。
我正在使用 Cdparanoia，但如果您希望使用 CDDA2WAV，命令行将是
$cdcap = system("cdda2wav", $count, "/mp3/cdda.wav");
重要的选项是 $count，它是要抓取的音轨数，然后是输出的 WAV 文件的路径。在我的示例中，这将转到我的 MP3 SCSI 驱动器上的 tmp 目录。
然后使用 Bladeenc 将 WAV 文件转换为 MP3 文件。
我编写这个 Perl 脚本是为了抓取 CD，而无需抓取和编码每个音轨，也无需使用 Cdparanoia 的批处理模式。这减少了所需的可用磁盘空间，因为 Cdparanoia 的批处理模式将抓取整个磁盘，并占用高达 600 兆的空间。
如果您想使用 Lame 或 Gogo，请将编码器行替换为
$enc = system("lame /mp3/cdda.wav $track -b 256");
$enc = system("gogo /mp3/cdda.wav $track -b 256");
以下是每个编码器的可用选项的转储。
Bladeenc
BladeEnc 0.91 (c) Tord Jansson Homepage: http://bladeenc.mp3.no
===============================================================================
BladeEnc is free software, distributed under the Lesser General Public License.
See the file COPYING, BladeEnc's homepage or www.fsf.org for more details.
Usage: bladeenc [global switches] input1 [output1 [switches]] input2 ...
General switches:
-[kbit], -br [kbit] Set MP3 bitrate. Default is 128 (64 for mono output).
-crc Include checksum data in MP3 file.
-delete, -del Delete sample after successful encoding.
-private, -p Set the private-flag in the output file.
-copyright, -c Set the copyright-flag in the output file.
-copy Clears the original-flag in the output file.
-mono, -dm Produce mono MP3 files by combining stereo channels.
-leftmono, -lm Produce mono MP3 files from left stereo channel only.
-rightmono, -rm Produce mono MP3 files from right stereo channel only.
-swap Swap left and right stereo channels.
-rawfreq=[freq] Specify frequency for RAW samples. Default is 44100.
-rawbits=[bits] Specify bits per channel for RAW samples. Default is 16.
-rawmono Specifies that RAW samples are in mono, not stereo.
-rawstereo Specifies that RAW samples are in stereo (default).
-rawsigned Specifies that RAW samples are signed (default).
-rawunsigned Specifies that RAW samples are unsigned.
-rawbyteorder=[order]Specifies byteorder for RAW samples, LITTLE or BIG.
-rawchannels=[1/2] Specifies number of channels for RAW samples. Does
the same as -rawmono and -rawstereo respectively.
Global only switches:
-quit, -q Quit without waiting for keypress when finished.
-outdir=[dir] Save MP3 files in specified directory.
-quiet Disable screen output.
-nocfg Don't take settings from the config-file.
-prio=[prio] Sets the task priority for BladeEnc. Valid settings are
HIGHEST, HIGHER, NORMAL, LOWER, LOWEST(default) and IDLE
-refresh=[rate] Refresh rate for progress indicator. 1=fastest, 2=def.
-progress=[0-8] Which progress indicator to use. 0=Off, 1=Default.
Input/output files can be replaced with STDIN and STDOUT respectively.
Lame
LAME version 3.50 (www.sulaco.org/mp3)
GPSYCHO: GPL psycho-acoustic model version 0.74.
USAGE : lame [options] <infile> [outfile]
<infile> and/or <outfile> can be "-", which means stdin/stdout.
OPTIONS :
-m mode (s)tereo, (j)oint, (f)orce or (m)ono (default j)
force = force ms_stereo on all frames. Faster and
uses special Mid & Side masking thresholds
-b <bitrate> set the bitrate, default 128kbps
(for VBR, this sets the allowed minimum bitrate)
-s sfreq sampling frequency of input file(kHz) - default 44.1
--resample sfreq sampling frequency of output file(kHz)- default=input sfreq
--mp3input input file is a MP3 file
--voice experimental voice mode
-v use variable bitrate (VBR)
-V n quality setting for VBR. default n=4
0=high quality,bigger files. 9=smaller files
-t disable Xing VBR informational tag
--nohist disable VBR histogram display
-h use (maybe) quality improvements
-f fast mode (low quality)
-k disable sfb=21 cutoff
-d allow channels to have different blocktypes
--athonly only use the ATH for masking
-r input is raw pcm
-x force byte-swapping of input
-a downmix from stereo to mono file for mono encoding
-e emp de-emphasis n/5/c (obsolete)
-p error protection. adds 16bit checksum to every frame
(the checksum is computed correctly)
-c mark as copyright
-o mark as non-original
-S don't print progress report, VBR histograms
Specifying any of the following options will add an ID3 tag
--tt <title> title of song (max 30 chars)
--ta <artist> artist who did the song (max 30 chars)
--tl <album> album where it came from (max 30 chars)
--ty <year> year in which the song/album was made (max 4 chars)
--tc <comment> additional info (max 30 chars)
MPEG1 samplerates(kHz): 32 44.1 48
bitrates(kbs): 32 48 56 64 80 96 112 128 160 192 224 256 320
MPEG2 samplerates(kHz): 16 22.05 24
bitrates(kbs): 8 16 24 32 40 48 56 64 80 96 112 128 144 160
Gogo
GOGO-no-coda ver. 2.24 (Feb 12 2000)
Copyright (C) 1999 PEN@MarineCat and shigeo
Special thanks to Keiichi SAKAI, URURI, Noisyu and Kei
This is based on LAME3.29beta and distributed under the LGPL
usage
gogo inputPCM [outputPCM] [options]
inputPCM is input wav file
if input.wav is `stdin' then stdin-mode
outputPCM is output mp3 file (omissible)
options
-b kbps bitrate [kpbs]
-br bps bitrate [ bps]
-silent dont' print progress report
-off {3dn,mmx,kni(sse),e3dn}
-v {0,..,9} VBR [0:high quality 9:high compression]
You should combine this with -b option
for only RAW-PCM input
-offset bytes skip header size
-8bit 8bit-PCM [dflt 16bit-PCM]
-mono mono-PCM [dflt stereo-PCM]
-bswap low, high byte swapping for 16bitPCM
-s kHz freq of PCM [dflt 44.1kHz]
-nopsy disable psycho-acoustics
-m {s,m,j} output format s:stereo, m:mono, j:j-stereo
-d kHz change sampling-rate of output MP3
-emh {n,c,5} de-emphasis
-lpf {on,off} 16kHz filter [dflt use if <= 128kbps; not use if >= 160kbps]
-test benchmark mode
-delete delete input file, after encoding
RipEnc 执行与上面的代码相同的任务，但是是用 shell 编写的，并且更易于使用 :)
这就是它的样子。
RipEnc version 0.7, Copyright (C) 1999 Michael J. Parmeley <mjparme@asde.com>, RipEnc comes with ABSOLUTELY NO WARRANTY There is currently NO encoding process running in the background Your encode.log file is 982607 bytes long. <Enter 'd' for details, 'v' to view the encode log, or 'del' to delete the encode log> 1) Change working directory....................[/megajukebox/tmp] 2) Choose encoder..............................[lame] 3) Choose ripper...............................[cdparanoia] 4) Choose id3 tool.............................[none] 5) Toggle between Manual and CDDB naming.......[manual] 6) Setup XMCD_LIBDIR variable for CDA..........[/var/X11R6/lib/xmcd] 7) Set preferred naming convention.............[artist-name_of_song.mp3] 8) Rip whole CD?...............................[no] 9) Set small hard drive option?................[no] 10) Please select your Cd-Rom device...........[/dev/cdrom] 11) Set the Bitrate for the encoded MP3's......[256] 12) List the files in your working directory 13) Start 14) About 15) Exit ?
Cd2mp3 是一个单程 cdda 到 MP3 编码器。它会将音频轨道转换为 MP3，而无需生成中间的 wav 文件。
以下是它在操作中的样子
[dj@megajukebox]$ cd2mp3 options ALL
Using language: 1 - English.
Translator: Gustavo Sverzut Barbieri(k-s) <gsbarbieri@hotmail.com>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Cd2Mp3 1.0 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Author: Gustavo Sverzut Barbieri (k-s) <gsbarbieri@hotmail.com.br>
*** device: -D/dev/cdrom type: -Icooked_ioctl
*** audio device: /dev/dsp
*** preset: tape
*** copyright: Yes
*** author:
*** album:
recording: '1' as 'track-1.mp3' (wait)
Ok! (recorded)
recording: '2' as 'track-2.mp3' (wait)
当然，您可以从命令行向其提供选项，以下是一个列表
dj@megajukebox]$ cd2mp3 --help %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Cd2Mp3 1.0 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Author: Gustavo Sverzut Barbieri (k-s) <gsbarbieri@hotmail.com.br> Usage: cd2mp3 options <track_number>="<track name>" ... <track_number>="<track name>"or: cd2mp3 options ALL (to record all tracks) or: cd2mp3 options LIST=<reclist_path> (to read pairs: <track_number>="<track name>" from a file) ou: cd2mp3 options PLAY=<track_number> VOL=[0..100] (only plays the track) Options: DEV=<cdrom_device> (default: /dev/cdrom) DEV_TYPE=[generic_scsi|cooked_ioctl] (default: cooked_ioctl) AUDIO_DEV=<audio_device> (default:/dev/dsp) LANGUAGE=<language_number> (LANGUAGE=help to see supported languages) COPYRIGHT=[YES|NO] PRESET=[phone|voice|fm|tape|hifi|cd|studio] (PRESET=help will give more info) ALBUM="<album's title>" AUTHOR="<author's name>"
基于 GUI 的编码器提供基于控制台的编码的所有功能，但将其全部包装在一个美观易用的界面中。Grip 和 RipperX 在操作上类似，两者都允许您选择 CD 上的一个、几个或所有音轨并进行转换。它们还提供 CDDB 支持，使您可以从服务器检索专辑和音轨信息，并节省您手动输入信息的时间。
在编码部分，我提到了 3 种不同的编码器：bladeenc、lame 和 gogo。主要的区别在于它们在编码方面的性能（尽管可用选项存在差异，这些选项在前面已列出）。
一个小例子。我从 CD 中抓取了一个音轨，然后使用不同的编码器对其进行了编码。所有编码器都在相同的系统条件下运行，并且都生成了立体声输出 mp3。
[dj@megajukebox]$ ls -l cdda.wav
-rw-rw-r-- 1 dj dj 59823164 Feb 10 00:56 cdda.wav
[dj@megajukebox]$ bladeenc cdda.wav -br 256
BladeEnc 0.91 (c) Tord Jansson Homepage: http://bladeenc.mp3.no
===============================================================================
BladeEnc is free software, distributed under the Lesser General Public License.
See the file COPYING, BladeEnc's homepage or www.fsf.org for more details.
Files to encode: 1
Encoding: ../test.wav
Input: 44.1 kHz, 16 bit, stereo.
Output: 128 kBit, stereo.
Completed. Encoding time: 00:05:58 (0.78X)
All operations completed. Total encoding time: 00:05:58
--------------------------------------------------------------------------------
[dj@megajukebox]$ lame cdda.wav -b 256
LAME version 3.50 (www.sulaco.org/mp3)
GPSYCHO: GPL psycho-acoustic model version 0.74.
Encoding ../test.wav to ../test.wav.mp3
Encoding as 44.1 kHz 128 kbps j-stereo MPEG1 LayerIII file
Frame | CPU/estimated | time/estimated | play/CPU | ETA
10756/ 10756(100%)| 0:02:28/ 0:02:28| 0:02:29/ 0:02:29| 1.9074| 0:00:00
--------------------------------------------------------------------------------
[dj@megajukebox]$ gogo cdda.wav -m s -b 256
GOGO-no-coda ver. 2.24 (Feb 12 2000)
Copyright (C) 1999 PEN@MarineCat and shigeo
Special thanks to Keiichi SAKAI, URURI, Noisyu and Kei
MPEG 1, layer 3 stereo
inp sampling-freq=44.1kHz out sampling-freq=44.1kHz bitrate=256kbps
inp sampling-freq=44.1kHz out sampling-freq=44.1kHz bitrate=128kbps
input file `../test.wav'
output file `../test.mp3'
{ 10751/ 10755} 100.0% ( 2.94x) re:[00:00:00.03] to:[00:01:35.42]
End of encoding
time= 95.430sec
看来 Gogo 在编码方面比 Bladeenc 和 Lame 具有更优化的算法。