歪林網誌

2011年2月9日星期三

C++ program to remove C/C++ style comments, while keep string content intact and line numbers of code unchnaged...

#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string>
#include <iostream>
#include <vector>
#include <string>

int my_fgets(std::string &str, FILE *fp, unsigned char to_remove_comments) {
    // read one line from file. if end of file return 0 otherwise return 1
    int ret=1;
    static unsigned char prev_linebreak;
    unsigned char ch;

    str.clear();

    while(1) {
        ch = fgetc(fp);

        if (feof(fp)) {
            prev_linebreak='\0';
            if (str.empty())
                ret=0;
            break;
        }

        if (ch=='\r') {
            prev_linebreak='\r';
            break;
        }

        if (ch=='\n') {
            if (prev_linebreak=='\r') {
                prev_linebreak='\0';
                continue;
            } else {
                prev_linebreak='\n';
                break;
            }
        }
        str+=ch;
    }

    if (to_remove_comments)
    {
        std::string tmpstr=str;

        static enum IN_COMMENT_T {
            IN_COMMENT_NOT,
            IN_COMMENT_WAIT_FOR_STAR_SLASH,
            IN_COMMENT_DOUBLE_QUOTE,
        } in_comment = IN_COMMENT_NOT;
        const char *p, *p_limit, *p_start;

        str.clear();
        p_start = tmpstr.c_str();
        p_limit = p_start + tmpstr.length();

        for(p=p_start; p<p_limit; p++) {
            switch(in_comment) {
            case IN_COMMENT_NOT:
                if (strncmp(p, "//", 2)==0) {
                    p=p_limit-1;
                    continue;
                } else if (strncmp(p, "/*", 2)==0) {
                    in_comment=IN_COMMENT_WAIT_FOR_STAR_SLASH;
                    p+=(sizeof("/*")-1)-1;
                } else if (*p=='"') {
                    // avoid case like '"'
                    if (p==p_start || *(p-1)!='\'')
                        in_comment=IN_COMMENT_DOUBLE_QUOTE;
                }
                break;
            case IN_COMMENT_WAIT_FOR_STAR_SLASH:
                if (strncmp(p, "*/", 2)==0) {
                    in_comment=IN_COMMENT_NOT;
                    p+=sizeof("*/")-1;
                }
                break;
            case IN_COMMENT_DOUBLE_QUOTE:
                if (*p=='"') {
                    // need to count how many '\' in the front. If it is even number then end of quote!
                    const char *q;
                    for(q=p-1; q>=p_start && *q=='\\'; q--);
                    if ((p-q)&1) {
                        // note (p-q)-1 is the number of '\\' before '"'.
                        // if ((p-q)-1) is odd, the " is escaped.
                        // if ((p-q)-1) is even, the " is a real close quotoation.
                        in_comment=IN_COMMENT_NOT;
                    }
                }
                break;
            default:
                break;
            }

            if (in_comment==IN_COMMENT_NOT || in_comment==IN_COMMENT_DOUBLE_QUOTE)
                str = str+*p;
        }

        if (ret==0)
            in_comment = IN_COMMENT_NOT;
    }

    return ret;
}

int
main(int argc, char **argv) {
    FILE *fp=NULL;
    std::string str;

    if (argc!=2) {
        fprintf(stderr, "remove C style comment in a text file and show in stdout\n");
        fprintf(stderr, "usage: %s file\n", argv[0]);
        goto MAIN_ERROR;
    }

    fp=fopen(argv[1], "rb");

    if (fp==NULL)  {
        fprintf(stderr, "error in open %s\n", argv[1]);
        goto MAIN_ERROR;
    }

    while(my_fgets(str, fp, 1))
        fprintf(stderr, "%s\n", str.c_str());


MAIN_ERROR:
    if (fp)
        fclose(fp);

    return 0;

}

2011年1月23日星期日

how to download audio from rthk server using wget?

wget --user-agent="NSPlayer/4.1.0.3938" --header="Pragma: \
no-cache,\
rate=1.000000,\
stream-time=240800,\
stream-offset=4294967295:4294967295,\
request-context=4,\
max-duration=2151082448,\
xPlayStrm=1,\
xClientGUID={3300AD50-2C39-46c0-AE0A-6420211E86C2},\
stream-switch-count=1,\
stream-switch-entry=ffff:1:0" \
http://202.177.192.111/rthk/radio1/20110122/2011012214.asf

2010年11月2日星期二

iPod HID Report Descriptor, what exactly is the content?

I am working on iPod HID interface recently.

As the first thing to do when working on HID interface, the lsusb -vv is used.

Here is the result:

Bus 002 Device 005: ID 05ac:1291 Apple, Inc. iPod Touch 1.Gen
 ...
 Interface Descriptor:
   bLength                 9
   bDescriptorType         4
   bInterfaceNumber        2
   bAlternateSetting       0
   bNumEndpoints           1
   bInterfaceClass         3 Human Interface Device
   bInterfaceSubClass      0 No Subclass
   bInterfaceProtocol      0 None
   iInterface              0
     HID Device Descriptor:
       bLength                 9
       bDescriptorType        33
       bcdHID               1.11
       bCountryCode            0 Not supported
       bNumDescriptors         1
       bDescriptorType        34 Report
       wDescriptorLength     208
      Report Descriptors:
        ** UNAVAILABLE **

It seems to me that wDescriptorLength is 208. I am not sure why the Report Descriptors is UNAVAILABLE.

According to this link: which somehow make the Report Descriptors available, the 208 bytes are:

00 ff 09 01 a1 01 75 08 26 80 00 15 00 09 01 85 01 95 05 82 02 01 09 01 85 02
09 82 02 01 09 01 85 03 95 0d 82 02 01 09 01 85 04 95 11 82 02 01 09 01 85 05
19 82 02 01 09 01 85 06 95 31 82 02 01 09 01 85 07 95 5f 82 02 01 09 01 85 08
c1 82 02 01 09 01 85 09 96 01 01 82 02 01 09 01 85 0a 96 81 01 82 02 01 09 01
0b 96 01 02 82 02 01 09 01 85 0c 96 ff 02 82 02 01 09 01 85 0d 95 05 92 02 01
01 85 0e 95 09 92 02 01 09 01 85 0f 95 0d 92 02 01 09 01 85 10 95 11 92 02 01
01 85 11 95 19 92 02 01 09 01 85 12 95 31 92 02 01 09 01 85 13 95 5f 92 02 01
01 85 14 95 c1 92 02 01 09 01 85 15 95 ff 92 02 01 c0

With the hidrd-convert tool, the above is parsed as shown below:

Usage Page (FF00h), ; FF00h, vendor-defined
 Usage (01h),
 Collection (Application),
  Report Size (8),
  Logical Maximum (128),
  Logical Minimum (0),
  Usage (01h), ReportID( 0x1), ReportCount(  5),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0x2), ReportCount(  9),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0x3), ReportCount( 13),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0x4), ReportCount( 17),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0x5), ReportCount( 25),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0x6), ReportCount( 49),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0x7), ReportCount( 95),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0x8), ReportCount(193),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0x9), ReportCount(257),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0xa), ReportCount(385),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0xb), ReportCount(513),  Input(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0xc), ReportCount(767),  Input(Variable, Buffered Bytes),
 
  Usage (01h), ReportID( 0xd), ReportCount(  5), Output(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0xe), ReportCount(  9), Output(Variable, Buffered Bytes),
  Usage (01h), ReportID( 0xf), ReportCount( 13), Output(Variable, Buffered Bytes),
  Usage (01h), ReportID(0x10), ReportCount( 17), Output(Variable, Buffered Bytes),
  Usage (01h), ReportID(0x11), ReportCount( 25), Output(Variable, Buffered Bytes),
  Usage (01h), ReportID(0x12), ReportCount( 49), Output(Variable, Buffered Bytes),
  Usage (01h), ReportID(0x13), ReportCount( 95), Output(Variable, Buffered Bytes),
  Usage (01h), ReportID(0x14), ReportCount(193), Output(Variable, Buffered Bytes),
  Usage (01h), ReportID(0x15), ReportCount(255), Output(Variable, Buffered Bytes),
 End Collection

However, with a 3rd party library that I used for the embedded system I am working on, I got a completely different result.

The size of descriptor is 96 bytes!!!!!!!!!!! (but not 208 bytes for lsusb -vv):

ff09 01a1 0175 0826 8000 1500 0901
950c 8202 0109 0185 0295 0e82 0201
8503 9514 8202 0109 0185 0495 3f82
0901 8505 9508 9202 0109 0185 0695
 0a92 0201 0901 8507 950e 9202 0109 0185
1492 0201 0901 8509 953f 9202 01c0

After parsing:

Usage Page (FF00h),                     ; FF00h, vendor-defined
 Usage (01h),
 Collection (Application),
   Report Size (8),
   Logical Maximum (128),
   Logical Minimum (0),
 
   Usage (01h), Report ID (1), Report Count (12), Input  (Variable, Buffered Bytes),
   Usage (01h), Report ID (2), Report Count (14), Input  (Variable, Buffered Bytes),
   Usage (01h), Report ID (3), Report Count (20), Input  (Variable, Buffered Bytes),
   Usage (01h), Report ID (4), Report Count (63), Input  (Variable, Buffered Bytes),
 
   Usage (01h), Report ID (5), Report Count (8),  Output (Variable, Buffered Bytes),
   Usage (01h), Report ID (6), Report Count (10), Output (Variable, Buffered Bytes),
   Usage (01h), Report ID (7), Report Count (14), Output (Variable, Buffered Bytes),
   Usage (01h), Report ID (8), Report Count (20), Output (Variable, Buffered Bytes),
   Usage (01h), Report ID (9), Report Count (63), Output (Variable, Buffered Bytes),
 End Collection

Which one should I believe???????

2009年10月3日星期六

歪林輸入法和 google 更緊密的整合

歪林輸入法已加入了 Goggle Suggest 、Goggle 拼音和 Goggle 翻譯的功能。

下載及安裝歪林輸入法後，可以按 Ctrl + W / E (先按 Ctrl 鍵，然後按 W 鍵或 E 鍵)，就可以啟動上述的功能。

那麼加入上面三個功能有什麼好處呢? 以下是加入上面三個功能的介紹：

Google Suggest:

Google Suggest 是當你在 Google 網頁輸入搜尋字的期間，Google 提出的建議字。舉個例子：

在 2009年7月尾，Google 為了配合香港人語言的需要，首創可以支援廣東話拼音的搜尋建議，這亦是 Google 香港首次為廣東話用戶特別推出的功能，讓大家的搜尋更得心應手。下面提供了一些範例，大家可以參考:

	想搵	輸入
娛樂名人	劉德華	lau tak wa lautakwa ltw
	陳奕迅	chan yik shun chanyikshun cys
	張學友	cheung hok yau cheunghokyau chy
卡通劇集	巾幗裊雄	gun kok hiu hung gunkokhiuhung gkhh
	老婆大人	lo po tai yan lopotaiyan lpty
	海賊王	hoi chak wong hoichakwong hcw

	想搵	輸入
資訊話題	電車男	din che nam dinchenam dcn
資訊話題	金融海嘯	kam yung hoi siu kamyunghoisiu kyhs
地方景點	北海道	pak hoi dou pakhoidou phd
	馬爾代夫	ma yi doi fu mayidoifu mydf
	太平山頂	tai ping shan dang taipingshandang tpsd

歪林輸入法已經將這功能整合了. 以下是示範：

Google 拼音

Google 提供了拼音漢字轉換

Google 運用智慧軟體系統對拼音關鍵字能進行自動中文轉換並提供相應提示(此功能只適用於台灣以外地區)。例如：輸入“shang wu tong”, Google 能自動提示 “您是不是要查：商務通”。如果您點選“商務通”，Google 將以“商務通”作為關鍵字進行搜尋。對於拼音和中文混和關鍵字，系統也能做有效轉換。對於拼音“lü”, “lüe”, “nü” 或 “nüe”，您可輸入 “lv”, “lve”, “nv” 或 “nve”。如果拼音中沒有空格，例如 “shangwutong”，Google 也會做相應處理，但是在多個拼音中加空格能提高轉換準確率和速度。

由於漢語的多音字和方言眾多，常用發音與實際發音常常有出入，更不用說拼音輸入中可能出現的錯誤了。Google 的拼音漢字轉換系統能支援模糊拼音搜尋，為用戶提示最符合的中文關鍵字，具有容錯和改正的功能。例如：輸入 “wan luo xing wen”, Google 會提示 “您是不是要查：萬羅興文蔓羅興文網絡新聞”, 其中 “網(wang)絡新(xin)聞” 是系統參考了可能會有的拼音錯誤後自動轉換的。點選其中任一提示，Google 將以其作為關鍵字進行搜尋。

2009年5月31日星期日

怎樣在 Linux 環境下，透過網絡共享數碼電視廣播 (DMB-TH 香港制式) ?

購買 ASUS 華碩 My Cinema-U3100 Mini USB 2.0 高清數碼電視接受棒
在某電腦，安裝 Ubuntu 9.0.4。建立一個用戶(以下假設是 yylam)
插入接收棒後，打 lsusb，看看 USB Vendor ID / Product ID 是否如下：

Bus 001 Device 005: ID 0b05:1721 ASUSTek Computer, Inc.
下載 v4l-dvb
- Click Application Menu, "Terminal". Assume you are in /home/yylam directory.
- Type the following:
  - sudo apt-get install mercurial"
  - hg clone http://linuxtv.org/hg/v4l-dvb
  - cd v4l-dvb
  - hg update -d "2008-12-7"
- Visit http://www.akbkhome.com/svn/asus_dvb_driver/src (At the time of writing this document, the svn revision is 124372).
- Download all the files there
  wget http://www.akbkhome.com/svn/asus_dvb_driver/src/dib3000mc.c
  wget http://www.akbkhome.com/svn/asus_dvb_driver/src/dib3000mc.h
  wget http://www.akbkhome.com/svn/asus_dvb_driver/src/dibusb-common.c
  wget http://www.akbkhome.com/svn/asus_dvb_driver/src/dibusb-mc.c
  wget http://www.akbkhome.com/svn/asus_dvb_driver/src/dvb-usb-firmware.c
  wget http://www.akbkhome.com/svn/asus_dvb_driver/src/dvb-usb-ids.h
  wget http://www.akbkhome.com/svn/asus_dvb_driver/src/dvb-usb-remote.c
  wget http://www.akbkhome.com/svn/asus_dvb_driver/src/dvb-usb-urb.c
  wget http://www.akbkhome.com/svn/asus_dvb_driver/src/initfrontend.h
  　
- Type the following:
  sudo apt-get install tofrodos
  dos2unix *.c
  dos2unix *.h
  mv dvb-usb-ids.h linux/drivers/media/dvb/dvb-usb/
  mv dibusb-common.c linux/drivers/media/dvb/dvb-usb/
  mv dvb-usb-remote.c linux/drivers/media/dvb/dvb-usb/
  mv dvb-usb-firmware.c linux/drivers/media/dvb/dvb-usb/
  mv dvb-usb-urb.c linux/drivers/media/dvb/dvb-usb/
  mv dibusb-mc.c linux/drivers/media/dvb/dvb-usb/
  mv dib3000mc.c linux/drivers/media/dvb/frontends/
  mv dib3000mc.h linux/drivers/media/dvb/frontends/
  mv initfrontend.h linux/drivers/media/dvb/frontends/
  
  hg update
  
  (resolve conflict in linux/drivers/media/dvb/dvb-usb/dibusb-common.c, keep the hg-server (the first) one)
  
  make
  sudo make install
  sudo make insmod
  
  sudo cp u3100dmbth.fw /lib/firmware
  (8071 bytes, md5sum a21d620949ab7ca4ed306a9bcfc2688f)
  　
Check if successfully loaded the driver:
- Unplug the DMT-TH USB stick.
- Restart the PC.
- Plug the DMB-TH USB stick. Wait a little while
- type lsmod to see if you see the following lines:
dib3000mc 24452 2 dvb_usb_dibusb_common
dibx000_common 11524 1 dib3000mc
- also see if /dev/dvb/adapter0 is created

Quick check if can play using mplayer:
　

Create a file channels.conf with the following content:

J2:586000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:821:823:82 iNews:586000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:831:834:83 HDJade:586000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:851:853:85 Jade:482000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:811:813:1 Pearl:482000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:841:843:2 Home:482000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:111:113:11 World:482000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:161:163:16 His:602000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:131:133:13 Her:602000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:141:143:14 News:602000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:121:123:12 Plus:602000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:151:153:15 CCTV:602000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:171:172:17 HDTV:602000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_16:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:92:82:19

Please note that: for Jade, Pearl, Home, Word, please change the frequency according to your district

慈雲山	482 000 000
青山	650 000 000
飛鵝山	562 000 000
金山	626 000 000
九龍坑山	546 000 000
南丫島	546 000 000
聶高信山	634 000 000

sudo apt-get install dvb-apps
sudo tzap -r -c channels.conf His (of course you should choose, instead of His, Jade etc)
you should be see the following:

tuning to 602000000 Hz
video pid 0x0083, audio pid 0x0085
status 1f | signal b9f0 | snr 0000 | ber 10000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal b9f0 | snr 0000 | ber b7f3914c | unc b7efb780 | FE_HAS_LOCK
status 1f | signal b9f0 | snr 0000 | ber b7f3914c | unc b7efb780 | FE_HAS_LOCK
status 1f | signal b9f0 | snr 0000 | ber b7f3914c | unc b7efb780 | FE_HAS_LOCK
status 1f | signal b9f0 | snr 0000 | ber b7f3914c | unc b7efb780 | FE_HAS_LOCK
status 1f | signal b9f0 | snr 0000 | ber b7f3914c | unc b7efb780 | FE_HAS_LOCK
　
sudo apt-get install mplayer
mplayer /dev/dvb/adapter0/dvr0
You should be able to watch TVB now.

Using VLC to share the video:

sudo chown yylam /dev/dvb/adapter0/frontend0
sudo chown yylam /dev/dvb/adapter0/
vlc dvb:// :dvb-frequency=482000000 --programs=11 -I dummy --sout '#standard{access=http,mux=ts}'    (ATV Home)
vlc dvb:// :dvb-frequency=482000000 --programs=16 -I dummy --sout '#standard{access=http,mux=ts}'    (ATV World)
vlc dvb:// :dvb-frequency=482000000 --programs=1   -I dummy --sout '#standard{access=http,mux=ts}'    (TVB Jade)
vlc dvb:// :dvb-frequency=482000000 --programs=2   -I dummy --sout '#standard{access=http,mux=ts}'    (TVB Pearl)

Then you should be able to watch the TV at http://192.168.0.2:8080 using Windows Media Player Classic.

To stream in Windows Media Player:

vlc dvb:// :dvb-frequency=482000000 --programs=11 -I dummy --sout '#transcode{vcodec=WMV1,vb=350,acodec=mp3,ab=32,channels=1}:duplicate{dst=std{access=http,mux=asf,dst=:1234}}}'

However, you need a special version of ffmpeg.

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