channel, and two left and right audio channels, the bitstream is 1.411 Mbps, therefore, it is necessary to use a DMA controller for transmission. (For more information about audio DMA, see DMA on the wince platform)
(2) audio mixing
If you want the sound driver model of Win
Part of this article refers to the blog from Droidphone (http://blog.csdn.net/droidphone/article/details/6271122), about Alsa writing a very good article, just a few examples. This article is a combination of examples to analyze the ALSA audio driver.Development environment: ubuntu10.04Target board: linux-2.6.37 (view Linux kernel information via command uname-r)Compiler: arm-none-linux-gnueabi-(None on behalf of compiler creator, such as: FSL for Fre
Bowen from Http://blog.csdn.net/droidphone Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx1. Origin of Asoc
Asoc--alsa system on Chip is built on a standard ALSA drive layer to better support a software system for embedded processors and audio codec in mobile devices. Before ASOC, the kernel had some support for
User:
$ Su-
Step 2:
Change the running level to enter the character interface:
# Init 3
Step 3:
CD to the driver directory
./Ati-driver-installer-10-12-x86.x86_64.run # Run the Driver Installation Package
Follow the prompts
Step 4:
After the installation is complete, use shutdown-R now to restart the system.
No con
. The two-channel, also known as stereo, has two lines in the hardware, with better sound quality and timbre than mono, but the amount of storage space occupied by digitizing is one-fold more than mono.Second, sound card driverFor security reasons, applications under Linux cannot operate directly on a hardware device such as a sound card, but must pass through a kernel-supplied driver to complete it. The essence of
sampling frequency ranges from 5 kHz to 44.1kHz or 48 kHz, but this does not mean that all the continuous frequencies in this range will be supported by hardware, in Linux, the most common sampling frequencies for audio programming are 11025Hz, 16000Hz, 22050Hz, 32000Hz, and 44100Hz. You can use the SNDCTL_DSP_SPEED IO control command to set the sampling frequency.
⑤ Read/write/dsp playback or recording
2.
://blog.csdn.net/droidphone Original, reproduced please indicate the source, thank you./*****************************************************************************************************/
The most important data structures for codec in 2. asoc Describe codec are: SND_SOC_CODEC,SND_SOC_CODEC_DRIVER,SND_SOC_ Dai,snd_soc_dai_driver, where the Snd_soc_dai and Snd_soc_dai_driver are also used in ASOC platform drive, platform and codec's Dai through S
!/*************************************** **************************************** * *********************/2. generally, ASOC registers snd_soc_platform_driver as a system's platform_driver. Do not be confused by the two similar terms. The former is only for the ASOC subsystem, the latter is a device driver model from Linux. What we need to do is:
Defines an instance with the snd_soc_platform_driver struc
Microsoft uaa bus driver for high definition audio solution:
Just install Microsoft's HD Audio patch.
Kb888111.exe download 1:
Http://blog.dhc.net.cn/batch.download.php? Aid = 17296.
Kb888111.exe download 2:
Http://www.htcath.org/Soft/ShowSoft.asp? Softid4245kb835221.exe download 1:
Http://couponmeister.com/blog/HD_Aud
DAPM and Dai widgets, the control parameters will be set later, and the function Snd_card_register of the registration card of ALSA will eventually be invoked.
ret = Snd_card_register (card->snd_card);
if (Ret
Summary: After machine-driven registrations, machine will be based on a platform device registered with "Soc_audio", and then in the driver's probe function of the platform with the same name, depending on the name in the Snd_soc_dai_link structure, Make a match to find the correspondin
platform and codec and Dai, filling them with several data structures, Then register the platform device. Of course also to implement the connection platform and codec dai_link corresponding OPS implementation, this example is smdk_ops, it only implements the Hw_params function: Smdk_hw_params. 2. Registered Platform Driver
According to the model of Linux equipment, there are platform_device, there must be
devices. Of course also to implement the connection platform and codec dai_link corresponding OPS implementation, this example is smdk_ops, it only implements the Hw_params function: Smdk_hw_params.2. Registered Platform Driver
According to the model of Linux equipment, there are platform_device, there must be platform_driver. ASOC's platform_driver is defined in the following file: Sound/soc/soc-core.c.
O
Port Environment (Bold font in redIs the modified content,Blue bold ChineseFor special attention)
1. host environment: centos 5.5 and 1 GB memory in vmare.
2. Integrated Development Environment: Elipse ide
3. compiling environment: Arm-Linux-GCC v4.4.3 and arm-None-Linux-gnueabi-GCC v4.5.1.
4. Development Board: mini2440, 2 m nor flash, 128 m nand Flash.
5, U-boot version: u-boot-2009.08
6, Linux: linux-2.6
controlsScontents show contents of all mixer simple controls (default command)Sset Sid p set contents for one mixer simple controlSget Sid get contents for one mixer simple controlControlsShow all controls for given cardContentsShow contents of all controls for given cardCset CID p set control contents for one controlCget CID get control contents for one control
2. Check that your audio system (different
SSI Audio Driver音频驱动的文章网上有很多,分析的也很具体,这里只记录本人在调试音频驱动的过程和理解。调试一个驱动,最主要的还是从本质上去理解它的工作原理,包括时钟,数据,中断,寄存器配置等。或许并不需要全部知道,但是追根到底会对以后的驱动有很大帮助。Audio driverlinux音频驱动的结构我个人感觉做得很漂亮,有面向对象编程的人不难看出这个结构与类图很想,将变化的东西封装了起来,层次清晰,方便理解和调试:CPU driver: Bus driver, such as I2S,SSI,AC97,ESAI,SPDIF. En
To solve the problem that the windows 7 audio/video driver cannot be installed or fails to be installed, many netizens say that the windows7 audio/video driver cannot be installed. Today, we will talk about the solution that the windows7 audio/video
The installation process is as follows:
1. Enter safe mode (otherwise the corresponding driver file will be restored automatically );2. Go to c: \ windows \ system32 \ drivers and delete hdaudio. sys and hdaudio. sys (if there are other hda headers, delete these two );3. Enter the Device Manager. Disable and then enable "Microsoft uaa bus driver for high definit
1. Uninstall the motherboard onboard sound driver through the Device Manager line, and then locate the audio driver for the video card in the video driver CD or the official website, and double-click to install it.
2. Right-click My Computer, select Properties, open System
Shen Jing, definition, sound card, flagship, audioWhen you see this article, it is estimated that you will soon be crashed because Windows 7 cannot install the sound card driver. Oh, don't worry. This article is your savior. I have already tested multiple computers, perfectly solves the problem of installation failure of Windows 7 audio/video driverThere is a premise that you have a sound card
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