H.264 無法 Streaming 問題解決

問題：
H.264 的影片中的 ATOM (影片的 index) 被放在影片的最後面，因此需要將整個檔案下載完之後才能夠播放。

解決方法：
使用工具將 ATOM 移到影片的最前端，即可一邊下載一邊播放。

OpenSource 工具：
1.QTIndexSwapper (Adobe AIR application by Renaun Erickson)
2.qt-faststart (C application by Mike Melanson)


為避免 qt-faststart.c 斷頭，特別將 Source Code 貼於此。

/*
* qt-faststart.c, v0.1
* by Mike Melanson (mike at multimedia.cx)
* This file is placed in the public domain. Use the program however you
* see fit.
*
* This utility rearranges a Quicktime file such that the moov atom
* is in front of the data, thus facilitating network streaming.
*
* Compile this program using:
* cc qt-faststart.c -o qt-faststart
* Invoke the program with:
* qt-faststart
*
* Notes: Quicktime files can come in many configurations of top-level
* atoms. This utility stipulates that the very last atom in the file needs
* to be a moov atom. When given such a file, this utility will rearrange
* the top-level atoms by shifting the moov atom from the back of the file
* to the front, and patch the chunk offsets along the way. This utility
* presently only operates on uncompressed moov atoms.
*/

#include
#include
#include

#define BE_16(x) ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
#define BE_32(x) ((((uint8_t*)(x))[0] << 24) | \
(((uint8_t*)(x))[1] << 16) | \
(((uint8_t*)(x))[2] << 8) | \
((uint8_t*)(x))[3])
#define BE_64(x) (((uint64_t)(((uint8_t*)(x))[0]) << 56) | \
((uint64_t)(((uint8_t*)(x))[1]) << 48) | \
((uint64_t)(((uint8_t*)(x))[2]) << 40) | \
((uint64_t)(((uint8_t*)(x))[3]) << 32) | \
((uint64_t)(((uint8_t*)(x))[4]) << 24) | \
((uint64_t)(((uint8_t*)(x))[5]) << 16) | \
((uint64_t)(((uint8_t*)(x))[6]) << 8) | \
((uint64_t)((uint8_t*)(x))[7]))

#define BE_FOURCC( ch0, ch1, ch2, ch3 ) \
( (uint32_t)(unsigned char)(ch3) | \
( (uint32_t)(unsigned char)(ch2) << 8 ) | \
( (uint32_t)(unsigned char)(ch1) << 16 ) | \
( (uint32_t)(unsigned char)(ch0) << 24 ) )

#define QT_ATOM BE_FOURCC
/* top level atoms */
#define FREE_ATOM QT_ATOM('f', 'r', 'e', 'e')
#define JUNK_ATOM QT_ATOM('j', 'u', 'n', 'k')
#define MDAT_ATOM QT_ATOM('m', 'd', 'a', 't')
#define MOOV_ATOM QT_ATOM('m', 'o', 'o', 'v')
#define PNOT_ATOM QT_ATOM('p', 'n', 'o', 't')
#define SKIP_ATOM QT_ATOM('s', 'k', 'i', 'p')
#define WIDE_ATOM QT_ATOM('w', 'i', 'd', 'e')
#define PICT_ATOM QT_ATOM('P', 'I', 'C', 'T')
#define FTYP_ATOM QT_ATOM('f', 't', 'y', 'p')

#define CMOV_ATOM QT_ATOM('c', 'm', 'o', 'v')
#define STCO_ATOM QT_ATOM('s', 't', 'c', 'o')
#define CO64_ATOM QT_ATOM('c', 'o', '6', '4')

#define ATOM_PREAMBLE_SIZE 8
#define COPY_BUFFER_SIZE 1024

int main(int argc, char *argv[])
{
FILE *infile;
FILE *outfile;
unsigned char atom_bytes[ATOM_PREAMBLE_SIZE];
uint32_t atom_type = 0;
uint64_t atom_size;
uint64_t last_offset;
unsigned char *moov_atom;
uint64_t moov_atom_size;
uint64_t i, j;
uint32_t offset_count;
uint64_t current_offset;
unsigned char copy_buffer[COPY_BUFFER_SIZE];
int bytes_to_copy;

if (argc != 3) {
printf ("Usage: qt-faststart \n");
return 0;
}

infile = fopen(argv[1], "rb");
if (!infile) {
perror(argv[1]);
return 1;
}

/* traverse through the atoms in the file to make sure that 'moov' is
* at the end */
while (!feof(infile)) {
if (fread(atom_bytes, ATOM_PREAMBLE_SIZE, 1, infile) != 1) {
break;
}
atom_size = BE_32(&atom_bytes[0]);
atom_type = BE_32(&atom_bytes[4]);

if ((atom_type != FREE_ATOM) &&
(atom_type != JUNK_ATOM) &&
(atom_type != MDAT_ATOM) &&
(atom_type != MOOV_ATOM) &&
(atom_type != PNOT_ATOM) &&
(atom_type != SKIP_ATOM) &&
(atom_type != WIDE_ATOM) &&
(atom_type != PICT_ATOM) &&
(atom_type != FTYP_ATOM)) {
printf ("encountered non-QT top-level atom (is this a Quicktime file?)\n");
break;
}

/* 64-bit special case */
if (atom_size == 1) {
if (fread(atom_bytes, ATOM_PREAMBLE_SIZE, 1, infile) != 1) {
break;
}
atom_size = BE_64(&atom_bytes[0]);
fseek(infile, atom_size - ATOM_PREAMBLE_SIZE * 2, SEEK_CUR);
} else {
fseek(infile, atom_size - ATOM_PREAMBLE_SIZE, SEEK_CUR);
}
}

if (atom_type != MOOV_ATOM) {
printf ("last atom in file was not a moov atom\n");
fclose(infile);
return 0;
}

/* moov atom was, in fact, the last atom in the chunk; load the whole
* moov atom */
fseek(infile, -atom_size, SEEK_END);
last_offset = (uint64_t)ftell(infile);
moov_atom_size = atom_size;
moov_atom = malloc(moov_atom_size);
if (!moov_atom) {
printf ("could not allocate 0x%llX byte for moov atom\n",
atom_size);
fclose(infile);
return 1;
}
if (fread(moov_atom, atom_size, 1, infile) != 1) {
perror(argv[1]);
free(moov_atom);
fclose(infile);
return 1;
}

/* this utility does not support compressed atoms yet, so disqualify
* files with compressed QT atoms */
if (BE_32(&moov_atom[12]) == CMOV_ATOM) {
printf ("this utility does not support compressed moov atoms yet\n");
free(moov_atom);
fclose(infile);
return 1;
}

/* close; will be re-opened later */
fclose(infile);

/* crawl through the moov chunk in search of stco or co64 atoms */
for (i = 4; i < moov_atom_size - 4; i++) {
atom_type = BE_32(&moov_atom[i]);
if (atom_type == STCO_ATOM) {
printf (" patching stco atom...\n");
atom_size = BE_32(&moov_atom[i - 4]);
if (i + atom_size - 4 > moov_atom_size) {
printf (" bad atom size\n");
free(moov_atom);
return 1;
}
offset_count = BE_32(&moov_atom[i + 8]);
for (j = 0; j < offset_count; j++) {
current_offset = BE_32(&moov_atom[i + 12 + j * 4]);
current_offset += moov_atom_size;
moov_atom[i + 12 + j * 4 + 0] = (current_offset >> 24) & 0xFF;
moov_atom[i + 12 + j * 4 + 1] = (current_offset >> 16) & 0xFF;
moov_atom[i + 12 + j * 4 + 2] = (current_offset >> 8) & 0xFF;
moov_atom[i + 12 + j * 4 + 3] = (current_offset >> 0) & 0xFF;
}
i += atom_size - 4;
} else if (atom_type == CO64_ATOM) {
printf (" patching co64 atom...\n");
atom_size = BE_32(&moov_atom[i - 4]);
if (i + atom_size - 4 > moov_atom_size) {
printf (" bad atom size\n");
free(moov_atom);
return 1;
}
offset_count = BE_32(&moov_atom[i + 8]);
for (j = 0; j < offset_count; j++) {
current_offset = BE_64(&moov_atom[i + 12 + j * 8]);
current_offset += moov_atom_size;
moov_atom[i + 12 + j * 8 + 0] = (current_offset >> 56) & 0xFF;
moov_atom[i + 12 + j * 8 + 1] = (current_offset >> 48) & 0xFF;
moov_atom[i + 12 + j * 8 + 2] = (current_offset >> 40) & 0xFF;
moov_atom[i + 12 + j * 8 + 3] = (current_offset >> 32) & 0xFF;
moov_atom[i + 12 + j * 8 + 4] = (current_offset >> 24) & 0xFF;
moov_atom[i + 12 + j * 8 + 5] = (current_offset >> 16) & 0xFF;
moov_atom[i + 12 + j * 8 + 6] = (current_offset >> 8) & 0xFF;
moov_atom[i + 12 + j * 8 + 7] = (current_offset >> 0) & 0xFF;
}
i += atom_size - 4;
}
}

/* re-open the input file and open the output file */
infile = fopen(argv[1], "rb");
if (!infile) {
perror(argv[1]);
free(moov_atom);
return 1;
}
outfile = fopen(argv[2], "wb");
if (!outfile) {
perror(argv[2]);
fclose(outfile);
free(moov_atom);
return 1;
}

/* dump the new moov atom */
printf (" writing moov atom...\n");
if (fwrite(moov_atom, moov_atom_size, 1, outfile) != 1) {
perror(argv[2]);
goto error_out;
}

/* copy the remainder of the infile, from offset 0 -> last_offset - 1 */
printf (" copying rest of file...\n");
while (last_offset) {
if (last_offset > COPY_BUFFER_SIZE)
bytes_to_copy = COPY_BUFFER_SIZE;
else
bytes_to_copy = last_offset;

if (fread(copy_buffer, bytes_to_copy, 1, infile) != 1) {
perror(argv[1]);
goto error_out;
}
if (fwrite(copy_buffer, bytes_to_copy, 1, outfile) != 1) {
perror(argv[2]);
goto error_out;
}

last_offset -= bytes_to_copy;
}

fclose(infile);
fclose(outfile);
free(moov_atom);

return 0;

error_out:
fclose(infile);
fclose(outfile);
free(moov_atom);
return 1;
}


vim 16 進位顯示

16 進位顯示

:%! xxd


切換回正常顯示

:%! xxd -r


流浪者之歌

人生就是不停畫著同心圓沙圈
一圈一圈擴大心的體驗

而你們
就是我願裡的沙
為我舉起刻骨的痕

測試 UDP Port 狀態

FreeBSD 需由 ports 安裝 nmap


nmap -p PORT -sU -P0 IP


結果：

[root@XXX] ~# nmap -p 1812 -sU -P0 127.0.0.1

Starting Nmap 5.21 ( http://nmap.org ) at 2010-07-19 17:22 CST
Nmap scan report for localhost (127.0.0.1)
Host is up (1.0s latency).
PORT STATE SERVICE
1812/udp open radius

Nmap done: 1 IP address (1 host up) scanned in 2.11 seconds
[root@XXX] ~# nmap -p 1815 -sU -P0 127.0.0.1

Starting Nmap 5.21 ( http://nmap.org ) at 2010-07-19 17:22 CST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00051s latency).
PORT STATE SERVICE
1815/udp closed unknown

Nmap done: 1 IP address (1 host up) scanned in 1.19 seconds


Perl 取代並寫回目標檔案內容

取代前 target.txt 內容

123abc
456abc


執行

perl -pi -e 's/abc$//g' target.txt


取代後 target.txt 內容

123
456


---

取代前 code.txt 內容

function abc()
{
echo('abc');
}

function def(){ echo('def'); }


執行

perl -pi -e 's/^(function )([a-z])/$1.uc($2)/eg' code.txt


取代後 code.txt 內容

function Abc()
{
echo('abc');
}

function Def(){ echo('def'); }



備註：
-p 是單行比對模式。
若需要多行比對，請增加 -0777 參數，此參數的意義為「將讀取分隔符號從 \n 變成 undef」，等同於等個檔案內容一次讀入做處理。多行比對同時需要加上 s 修飾字。

約定？

「那約定怎麼辦？」我說。

「你瞭解我的，那只是一時昏頭」她回。
「真是多虧了那一句話點醒我」
「那些問題你能解決嗎？」

「再說吧」
我瞇著淚眼笑。

你懂

想著
想著
想著一切

總覺得飄渺

或許
在那踏實的背後
躲著一股
小小鼻酸

只有
你懂

不悔

叮啷一聲
果汁店收銀機驚醒了我的渾沌

難道
這竟是他們戲稱的
賺那買藥錢

怎麼我會在這兒
只為那
不悔的十年之約

為她摘下星星

美味咖哩作法

1.大蒜、洋蔥 炒至褐色軟透
2.加水後倒入果汁機
3.加入切碎的 胡蘿蔔 一起打碎
4.倒回鍋中，加入 馬鈴薯 與 辣椒，煮 20分鐘
5.取出 馬鈴薯 與 辣椒，過篩後倒回鍋中
6.放涼湯汁
7.加入 咖哩塊、奶油 與 砂糖煮化
8.肉煎過，加入鍋中熬煮 2小時，放置一晚自然涼(或肉煎熟後直接放入醬汁中食用)

憂傷瞬間

淡淡地憂傷
我感覺到

臉頰上的涼意 是蒸發中的悲傷
心裡曾經的裂痕 無聲地淌出了熔岩
滾燙著吞噬掉唯一的幸福

只剩一片孤寂的煙
飄散在下午 2點 39分的面前