Allocate Pin Buffer

CTransformFilter::DecideBufferSize

ALLOCATOR_PROPERTIES Structure

和CMediaType::SetSampleSize有關

如果沒對映好，送到pin腳的資料就會少

DirectShow MediaType

AM_MEDIA_TYPE http://msdn2.microsoft.com/en-us/library/aa930737.aspx

typedef struct _MediaType{
GUID majortype;
GUID subtype;
BOOL bFixedSizeSamples;
BOOL bTemporalCompression;
ULONG lSampleSize;
GUID formattype; .
IUnknown* pUnk;
ULONG cbFormat;
/* [size_is] */ BYTE __RPC_FAR* pbFormat;
} AM_MEDIA_TYPE;

formattype
Registered (GUID) format type.
pbFormat
Pointer to the format section of the media type. The layout of this is determined by the format type GUID.
-> 指向這個media type的structure


CMediaType::SetFormatType -> specifies the format type
CMediaType::SetFormat -> initializes the format block.

RTSP 簡圖

Client               Server
  |                    |
  | ---- DESCRIBE ---> |
  | <----------------- |SDP, video type, length...
  |                    |
  | ----- SETUP -----> |client address, port
  | <----------------- |server address, port
  |                    |
  | ------ PLAY -----> |
  | <----------------- |
  |                    |
  | <----------------- |
  |    Media Stream    | RTP on UDP
  | <----------------- |
  |                    |
  | ----- PAUSE -----> |
  | <----------------- |
  |                    |
  | ---- TEARDOWN ---> |
  | <----------------- |
  |                    |

Real Time Streaming Protocol from Wikipedia

MPEG-4 AAC Format

AAC封裝主要分三類

1. Multiplex (LATM, M4Mux)
2. Storage(MPEG-4 FileFormat, ADIF)
3. Transmission (ADTS, LOAS)
   

AAC的SDP裡的
AudioSpecificConfig: (ISO/IEC 14496-3, Table1.13)

5 bits: object type

4 bits: frequency index
if (frequency index == 15)
24 bits: frequency
4 bits: channel configuration
1 bit: frame length flag
1 bit: dependsOnCoreCoder
1 bit: extensionFlag

ref:

• Understanding AAC RFC 3016 - RTP Payload Format for MPEG-4 Audio/Visual Streams
• RFC 3640 - RTP Payload Format for Transport of MPEG-4 Elementary Streams
• ISO/IEC 14496-3
• Session Description Protocol

AV簡史

以年分從1874到2007寫出Audio和Video的發展
The Short History of Audio/Video Technology

找不到strstrea.h

在Visual Studio 2002的project，拿到Visual Studio 2005去build會有以下錯誤訊息：

fatal error C1083: Cannot open include file: 'strstrea.h'

好像是Visual Studio 2003後就不用這個檔案了，所以要把strstrea.h改成strstream

在Ubuntu Linux裡build FAAD2

在Ubuntu 7.04 (Feisty Fawn)裡build faad2-2.5遇到一些問題：

Ubuntu裡要先裝

sudo apt-get install autoconf
sudo apt-get install automake
sudo apt-get install libtool

改幾個和BMP有關的檔(不然configure不過)
/faad2/configure.in
/faad2/plugins/xmms/src/Makefile.am
/faad2/plugins/Makefile.am

執行

autoreconf -vif
./configure --with-mp4v2
make
sudo make install

參考：
How to compile ffmpeg on Mac and Linux

Windows CE的build

Windows CE的build都是從BldDemo.bat產生run-time image.
其中依序呼叫：
1. Cebuild.bat
2. Buildrel.bat
3. Makeimg.exe

參考: Build flow in BldDemo.bat

但是MSDN的Build phases畫的圖很怪，要先compile才sysgen?

Checko's Blog寫的更好

[WindowsCE小技巧] Build出來的東西沒有在image裡

好像常會發生，都是prebuild搞的鬼...

Copy your binary, symbols, map into %_FLATRELEASEDIR%

Find out what package your file is in

1. Cd %_FLATRELEASEDIR%
2. "findstr /i [your filename] *.bsm.xml" Ex: findstr /i nk.exe *.bsm.xml

This should return a package's xml file, for example oemxipkernel.bsm.xml. This tells you that it's in the OS package.

Find the prebuilt package and delete it

1. cd prebuilt
2. del oemxipkernel.cab.pkg

Makeimg

詳全文

Windows Mobile上的PythonCE

Windows Mobile上有跑Python的PythonCE.

PythonCE for Windows Mobile Smartphone

Windows Media Player與副檔名

Windows Media Player在播ASF, MP3 WMA和WMV時，不是用DirectShow(不確定PC上的是不是也一樣)。硬要用DirectShow的話，要改註冊檔：
[HKEY_CLASSES_ROOT\Media Type\Extensions\.xxx]
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Multimedia\WMPlayer\Extensions\.xxx]
其中Runtime和和Permissions請看: File Name Extension Registry Settings

這裡也要加，不過好像也沒差...
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MediaPlayer\MLS\Extensions]

Windows CE Build筆記 (未完)

wince.bat

blddemo.bat invokes: sysgen, build, buildrel, and makeimg.
first 2 are invoked indirectly through cebuild.bat

Generating WinCE System: Sysgen.bat
sysgen.bat executes cesysgen.bat, where the modules and components.
include modules
CE_MODULES=coredll filesys nk
component included in a module
set COREDLL_COMPONENTS=coremain coreloc lmem thunks

BIB(Binary Image Builder Files) files specify the name and location of modules that must be included in the image.

filesys module initializes the Windows registry.

WindowsCE的printf

WindowsCE裡有些值用printf印不出來，要用DEBUGMSG, RETAILMSG, 或ERRORMSG

等巨集，NKDbgPrintfW

The debug printf messages are invaluable at some stages of development. However, we found drawbacks when using the non-Pocket PC reference platform. Basically, ActiveSync and EVC Remote Tools were frustratingly unreliable. After a successful build and download of a Rawether sample application and the PCANDIS4 driver the EVC Remote Tools may simply refuse to connect again until the PDA was rebooted.

http://www.pocketpcjunkies.com/Uwe/Forum.aspx/wince-pb/806/May-I-print-message-via-serial-port-instead-of-using-RETAILMSG

3GPP和3GPP2

3GPP 和3GPP2是不同的組織。
以通訊協定來看：3GP是GSM，3GPP2是CDMA2000
從檔案格式來看：3GP/3GPP可視為簡化的MP4檔案格式

要連WindowsMobile6請先裝SP1

用Visual Studio 2005的工具Remote Registry Editor連不到WindosMobile 6的機器，沒有錯！又要裝VS 2005 Service Pack 1 (SP1)。

OpenMAX API

OpenMAX是一套Khronos Group 推出的跨平台多媒體API，由上到下分為三層：Application Layer(AL)、(Integration Layer) IL和Development Layer (DL)，免收權利金。目前有六個部門在管理：
(1)帶頭 - TI
(2) AL - Nvidia
(3) IL - TI
(4) Video DL - Motorola
(5) Still Image DL - ARM
(6) Speech/Audio - Intel。

IL顧名思義就是可以整合各種media framework之下，如Microsoft DirectShow、SDL、Linux GStreamer、Symbian MDF和MMAPI (JSR 135)，我猜IL應該就像DirectShow的Filter。DL介於個codecs和CPU、DSP或硬體加速之間。

示意圖:
-----------------
| Application |
| OpenMAX AL |
| OpenMAX IL |
| Codecs |
| OpenMAX DL |
| Physical H/W |
-----------------

OpenMAX白皮書 - OpenMAX和DirectShow、Gstreamer和MDF的整合。

WindowsCE除錯

• Windows CE Virtual Memory Layout for Debugging
• Resolving Symbols Manually on Windows CE (ADDRESS --> SYMBOL)

Platform Builder的Target Control Debugging Commands

WindowsCE介紹

WinHEC 2004裡的Embedded Design: Architecture and Engineering Advances有佷多WindowsCE架構的投影片。

Windows Mobile 5和6的比較
最主要好像是Exchange、Windows Live和一些messaging的東西...
from: Jason Langridge's WebLog

Windows CE5.0不支援midi的DirectShow Filter

看到這個才恍然大悟：

Effective with Windows CE 5.0, Windows CE no longer provides a MIDI filter for DirectShow. Third party solutions for MIDI support through DirectShow are still possible.

DirectShow Migration

用到dynamic_cast運算子時要加/GR

程式build可以過，但是run到dynamic_cast運算子時，會出現access deny(coredll.dll)，然後hang住。

Sources檔要要加上/GR的compile option才可以。

讀更多: Compiler Options照字母排