后使用快捷导航没有帐号？
重定义Modern UI,打造完美Windows全新体验
查看: 5004|回复: 3
积分72最后登录精华0阅读权限20主题UID61644帖子PB币1926 威望0 贡献0 技术6 活跃34
PCBETA Milestone, 积分 72, 距离下一级还需 128 积分
UID61644帖子PB币1926 贡献0 技术6 活跃34
经过测试可行
原文地址：
http://www.dr-lex.be/software/cm6206.html
(14.71 KB, 下载次数: 134)
18:55 上传
下载次数: 134
驱动下载积分: PB币 -1
(145.04 KB, 下载次数: 104)
18:55 上传
下载次数: 104
测试声音下载积分: PB币 -1
(18.32 KB, 下载次数: 102)
18:55 上传
下载次数: 102
驱动源码下载积分: PB币 -1
What is it?
This is a small program that activates the analog and S/PDIF outputs on USB devices that are based on the C-Media CM6206 surround sound chip (sometimes also referred to as CMI6206). One of the common cheap devices that uses this IC and that's sold on eBay can be seen in the photo at the right. It's a 5.1 device but the IC supports up to 7.1 audio. The one I bought had a sticker with a serial number &&, but there may be other devices that use this IC. Some major brands also use this chip, for instance Zalman uses it in their ZM-RS6F USB headphones.
The problem with the CM6206 chip, at least the one used in the device I bought, is that it does not produce any audio output at all when plugged in. It behaves like a fully compliant audio device, it can be selected in the audio control panel and the 6 channels can be assigned using Audio MIDI setup. But there is no sound. The same symptoms occur in Windows, until the C-Media driver is installed. Apparently, the device boots with its outputs disabled, and the only thing the ‘driver’ does is send some specific configuration requests to enable both the analog outputs and the optical S/PDIF.
So I started gathering information: I used a USB sniffer to look at the packets sent to the device in Windows with and without the driver installed, and I found some useful clues in the Linux ALSA driver source code and mailinglist. Combined with some sample code from the XCode Developer kit, I managed to create a simple program that sends the crucial packets, enabling both the analog outputs and the S/PDIF. So there you have it, surround sound on your Mac for the price of a cheap USB audio card on eBay.
Mind that this is the most braindead solution to this problem possible. It's not a driver, nor a neat GUI-based program. It's a simple command that needs to be executed in a terminal. If there's enough demand, I may try to convert it to a more user-friendly GUI or something that invisibly runs in the background as a driver.
Download the cm6206 enabler (zip archive, 15KiB)
To use it, first plug in your CM6206-based audio device, then run the program.
If you have no idea how to use console commands, don't worry. It seems that in the latest OS X versions, one can simply double-click executable files. If not, you can still easily make the program double-clickable. Just rename it to “mand”. If you then double-click it, it should open in Terminal and run.
It seems you need OS X 10.5.x or 10.6.x to make this work. The program runs on any OS X version starting from 10.3.9, but I have so far been unable to connect to the CM6206 in OS X 10.4.11, and I assume any lower version will fail too. For some reason unknown, all interfaces on the device are “in use” (error e00002c5) no matter what I try. If anyone has a clue how to fix this, I'm interested.
The source code (18KiB) is also available. Feel free to enhance it or turn it into a proper USB device driver. Next to making the thing more user-friendly, there are some other things that could be improved, like enabling stereo or bias voltage on the microphone input.
Setting up surround sound
Unfortunately, at the time of this writing it's still quite a hassle to get surround sound properly set up on OS X. Here's a checklist of what you should do to get 5.1 sound out of any USB sound card.
Log in using an administrator account. Otherwise OS X will silently ignore any changes you make to the multichannel setup.
In the Sound control panel, select the USB audio output device.
Open the ‘Audio Midi Setup’ program in your Applications/Utilities folder.
Select the USB card as output device and set the sampling rate to 44100 or 48000 depending on the rate of the audio you want to play (for a movie it's most likely 48k).
Set the number of channels to 6 (6ch-16bit).
Click ‘Configure speakers’ and choose “5.1 surround”. You can click the buttons to test each speaker, but mind that the test sound is an awfully loud noise. It's better to use the method described below.
In your media player (e.g. VLC), you may also need to select the USB audio device as output device.
To test if all channels work, you can download an AC3 test sound below. I recommend VLC to play the file, as it's the only player I currently know that properly assigns the channels, although you may also have success with QuickTime combined with Perian. The following file can also be used to roughly calibrate the volumes if you're using a mixed set-up, although I noticed that for many movies, the rear speaker volume needs an additional boost for reasons unknown*. Mind that for movie soundtracks you'll also need to apply a +10dB boost to the LFE channel to bring it at the correct level.
Download 5.1 channel test file (zip archive, 145KiB)
*: I suspect that AC3 streams can specify a relative gain for the rear/center channels, and that VLC ignores this gain when decoding the stream, but I can be wrong about this. At any rate, this issue, as wel as the lack of multichannel sound card support in Plex, annoyed me enough to get a proper 5.1 decoder connected through S/PDIF, so I'm currently not using the cm6206-based sound card anymore.
Version history
1.0 (): Initial release.
<p id="rate_591" onmouseover="showTip(this)" tip="膜拜远景大神！&PB币 + 1
" class="mtn mbn">
积分447最后登录精华0阅读权限30主题UID569382帖子PB币3279 威望15 贡献0 技术4 活跃10
PCBETA Beta1, 积分 447, 距离下一级还需 53 积分
UID569382帖子PB币3279 贡献0 技术4 活跃10
哇.耳机都能5.1声道了呀现在,真是nb呀.
积分1579最后登录精华0阅读权限50主题UID348940帖子PB币5758 威望65 贡献0 技术199 活跃471
PCBETA RC1, 积分 1579, 距离下一级还需 1421 积分
UID348940帖子PB币5758 贡献0 技术199 活跃471
回二楼，早就有啦 效果一般 毕竟空间太小
积分757最后登录精华0阅读权限40主题UID97889帖子PB币6143 威望0 贡献0 技术0 活跃7
PCBETA Beta2, 积分 757, 距离下一级还需 743 积分
UID97889帖子PB币6143 贡献0 技术0 活跃7
烤，我的音箱才2.1 ZZzz
7周年庆典勋章
远景7周年一路有你
#没攀过峻岭，何以览美景#
英特尔邀请你加入核心粉丝俱乐部，共享最“芯”科技！
关注远景官方微信
Copyright (C) 2005-, All rights reserved
Powered by Discuz!&&沪ICP备号
请勿发布违反中华人民共和国法律法规的言论，会员观点不代表远景论坛官方立场。&#xe602; 下载
&#xe60c; 收藏
该文档贡献者很忙，什么也没留下。
&#xe602; 下载此文档
正在努力加载中...
骅讯(cmedia)系列ic特性说明大全
下载积分：1000
内容提示：
文档格式：TXT|
浏览次数：0|
上传日期： 05:38:01|
文档星级：&#xe60b;&#xe612;&#xe612;&#xe612;&#xe612;
该用户还上传了这些文档
骅讯(cmedia)系列ic特性说明大全.TXT
官方公共微信