x265原始碼分析:main函式及CLIOptions結構體解釋
阿新 • • 發佈:2018-10-31
/**
* 返回碼資訊:
* 0 – 編碼成功;
* 1 – 命令列解釋失敗;
* 2 – 編碼器開啟失敗;
* 3 – 生成流頭部失敗;
* 4 – 編碼出錯;
* 5 – 開啟csv檔案失敗.
*/
int main(int argc, char **argv)
{
// 獲取控制檯視窗的標題,儲存在靜態陣列orgConsoleTitle中
GetConsoleTitle(orgConsoleTitle, CONSOLE_TITLE_SIZE);
// 取消電源管理,避免睡眠、待機
SetThreadExecutionState(ES_CONTINUOUS| ES_SYSTEM_REQUIRED|ES_AWAYMODE_REQUIRED);
ReconPlay* reconPlay = NULL;
CLIOptions cliopt;
// 分析命令列引數,對編碼器的引數進行設定,開啟相關檔案
if (cliopt.parse(argc, argv))
{
cliopt.destroy();
if (cliopt.api)
cliopt.api->param_free(cliopt.param);
exit(1);
}
x265_param* param = cliopt.param;
const x265_api* api = cliopt.api;
/* This allows muxers to modify bitstream format */
cliopt.output->setParam(param);
if (cliopt.reconPlayCmd)
reconPlay = new ReconPlay(cliopt.reconPlayCmd, *param);
// 命令列解釋階段,依據引數profile的值可選擇不同的 libx265 API.
// 開啟編碼器
x265_encoder *encoder = api->encoder_open(param);
if (!encoder)
{
x265_log(param, X265_LOG_ERROR, "failed to open encoder\n");
cliopt.destroy();
api->param_free(param);
api->cleanup();
exit(2);
}
// 獲取編碼引數
api->encoder_parameters(encoder, param);
if (cliopt.csvfn)
{
cliopt.csvfpt = x265_csvlog_open(*api, *param, cliopt.csvfn, cliopt.csvLogLevel);
if (!cliopt.csvfpt)
{
x265_log_file(param, X265_LOG_ERROR, "Unable to open CSV log file <%s>,
aborting\n", cliopt.csvfn);
cliopt.destroy();
if (cliopt.api)
cliopt.api->param_free(cliopt.param);
exit(5);
}
}
// 當按下Ctrl-C的時候,當前執行程式呼叫指標函式sigint_handler 執行完後,再返回原
// 來執行的地方接著往下走。 此處將變數b_ctrl_c設定為1,停止當前編碼工作。
if (signal(SIGINT, sigint_handler) == SIG_ERR)
x265_log(param, X265_LOG_ERROR, "Unable to register CTRL+C handler: %s\n", strerror(errno));
// 定義x265的輸入pic_orig和輸出pic_out
x265_picture pic_orig, pic_out;
x265_picture *pic_in = &pic_orig; // 獲取x265的輸入pic_orig的地址
// Allocate recon picture if analysisMode is enabled
std::priority_queue<int64_t>* pts_queue = cliopt.output->needPTS() ? new
std::priority_queue<int64_t>() : NULL;
x265_picture *pic_recon = (cliopt.recon || !!param->analysisMode || pts_queue
|| reconPlay || cliopt.csvLogLevel) ? &pic_out : NULL;
// 輸入、輸出的幀數
uint32_t inFrameCount = 0;
uint32_t outFrameCount = 0;
x265_nal *p_nal;
x265_stats stats;
uint32_t nal;
int16_t *errorBuf = NULL;
int ret = 0;
// 如果不需要複製sps和pps放在每個關鍵幀的前面,則直接編碼視訊流的頭
if (!param->bRepeatHeaders)
{
if (api->encoder_headers(encoder, &p_nal, &nal) < 0)
{
x265_log(param, X265_LOG_ERROR, "Failure generating stream headers\n");
ret = 3;
goto fail;
}
else
// 更新總位元組數:增加頭部位元組數目
cliopt.totalbytes += cliopt.output->writeHeaders(p_nal, nal);
}
api->picture_init(param, pic_in);
if (cliopt.bDither)
{
errorBuf = X265_MALLOC(int16_t, param->sourceWidth + 1);
if (errorBuf)
memset(errorBuf, 0, (param->sourceWidth + 1) * sizeof(int16_t));
else
cliopt.bDither = false;
}
// main encoder loop(編碼主迴圈)
while (pic_in && !b_ctrl_c)
{
pic_orig.poc = inFrameCount;
if (cliopt.qpfile)
{
if (!cliopt.parseQPFile(pic_orig))
{
x265_log(NULL, X265_LOG_ERROR, "can't parse qpfile for frame %d\n",
pic_in->poc);
fclose(cliopt.qpfile);
cliopt.qpfile = NULL;
}
}
// 待編碼的幀數大於0 且 輸入的幀數大於或等於將要編碼的幀數
if (cliopt.framesToBeEncoded && inFrameCount >= cliopt.framesToBeEncoded)
pic_in = NULL;
// 成功讀取一幀,則輸入幀數增加1
else if (cliopt.input->readPicture(pic_orig))
inFrameCount++;
else
pic_in = NULL;
if (pic_in)
{
if (pic_in->bitDepth > param->internalBitDepth && cliopt.bDither)
{
x265_dither_image(*api, *pic_in, cliopt.input->getWidth(), cliopt.input->getHeight(), errorBuf, param->internalBitDepth);
pic_in->bitDepth = param->internalBitDepth;
}
/* Overwrite PTS */
pic_in->pts = pic_in->poc;
}
// 進行編碼入口函式,讀入幾十幀(具體多少幀依賴命令列引數的設定)之後才開始編碼。
// numEncoded是本次編碼出來的幀數,大部分情況下為1,如果是負數表示編碼出錯。
int numEncoded = api->encoder_encode(encoder, &p_nal, &nal, pic_in, pic_recon);
if (numEncoded < 0)
{
b_ctrl_c = 1;
ret = 4;
break;
}
if (reconPlay && numEncoded)
reconPlay->writePicture(*pic_recon);
if (numEncoded && pic_recon && cliopt.recon)
cliopt.recon->writePicture(pic_out);
if (nal)
{
cliopt.totalbytes += cliopt.output->writeFrame(p_nal, nal, pic_out);
if (pts_queue)
{
pts_queue->push(-pic_out.pts);
if (pts_queue->size() > 2)
pts_queue->pop();
}
}
// 列印編碼幀的具體資訊
cliopt.printStatus(outFrameCount);
if (numEncoded && cliopt.csvLogLevel)
x265_csvlog_frame(cliopt.csvfpt, *param, *pic_recon, cliopt.csvLogLevel);
} // 編碼主迴圈結束
/* Flush the encoder */
// 前面讀入幾十幀之後才開始編碼,此處其實就是處理對應的倒數的幾十幀,將其儲存
while (!b_ctrl_c)
{
... ...
}
/* clear progress report */
if (cliopt.bProgress)
fprintf(stderr, "%*s\r", 80, " ");
fail:
... ...
return ret;
}
x265 的各種引數主要是通過CLIOptions結構體及相關函式傳遞給x265的各API,接下來我們分析CLIOptions結構體的構成及重要函式的功能,如下:
/* 命令列介面 */
struct CLIOptions
{
InputFile* input; // 輸入檔案,抽象類, 定義在 \input\input.h 中
ReconFile* recon; // 重構檔案,抽象類,定義在 \output\output.h 中
OutputFile* output; // 輸出檔案,抽象類,定義在 \output\output.h 中
FILE* qpfile; // 量化因子檔案指標
FILE* csvfpt; // csv日誌檔案指標
const char* csvfn; // csv日誌檔名
const char* reconPlayCmd;
const x265_api* api; //
x265_param* param; // x265編碼器引數集
bool bProgress; // 是否輸出編碼進度和其他一些編碼狀態資料
bool bForceY4m; // 如果輸入檔案是Y4M格式,需要強制指定輸入格式
bool bDither;
int csvLogLevel; // csv日誌級別,log level定義在 x265.h中
uint32_t seek; // 輸入視訊起始需要跳過的幀數
uint32_t framesToBeEncoded; // 待編碼的幀數
uint64_t totalbytes; // 已編碼的資料位元組數
int64_t startTime; // 起始編碼時間點
int64_t prevUpdateTime; // 上一次編碼資訊輸出的時間點
/* in microseconds,相鄰兩次編碼狀態輸出的最小時間間隔,單位微妙 */
static const int UPDATE_INTERVAL = 250000;
// 建構函式,初始化上述各成員變數
CLIOptions()
{
… … … …
}
void destroy();
void printStatus(uint32_t frameNum); // 列印編碼狀態資訊
bool parse(int argc, char **argv); // 解釋命令列引數
bool parseQPFile(x265_picture &pic_org); // 解釋量化因子QP檔案
};
/* 列印編碼狀態資訊 */
void CLIOptions::printStatus(uint32_t frameNum)
{
char buf[200];
int64_t time = x265_mdate();
// 是否輸出編碼狀態資訊取決於:進度開關、當前編碼幀數、上次資訊輸出和當前時間的間隔
if (!bProgress || !frameNum || (prevUpdateTime && time - prevUpdateTime < UPDATE_INTERVAL))
return;
// 計算編碼幀率和位元速率
int64_t elapsed = time - startTime;
double fps = elapsed > 0 ? frameNum * 1000000. / elapsed : 0;
float bitrate = 0.008f * totalbytes * (param->fpsNum / param->fpsDenom) / ((float)frameNum);
if (framesToBeEncoded)
{
int eta = (int)(elapsed * (framesToBeEncoded - frameNum) / ((int64_t)frameNum * 1000000));
sprintf(buf, "x265 [%.1f%%] %d/%d frames, %.2f fps, %.2f kb/s,
eta %d:%02d:%02d", 100. * frameNum / framesToBeEncoded, frameNum,
framesToBeEncoded, fps, bitrate, eta / 3600, (eta / 60) % 60, eta % 60);
}
else
sprintf(buf, "x265 %d frames: %.2f fps, %.2f kb/s", frameNum, fps, bitrate);
fprintf(stderr, "%s \r", buf + 5);
SetConsoleTitle(buf);
fflush(stderr); // needed in windows
prevUpdateTime = time;
}
/* 解釋命令列引數 */
bool CLIOptions::parse(int argc, char **argv)
{
bool bError = false;
int bShowHelp = false;
int inputBitDepth = 8;
int outputBitDepth = 0;
int reconFileBitDepth = 0;
const char *inputfn = NULL; // 輸入檔名
const char *reconfn = NULL; // 重構檔名
const char *outputfn = NULL; // 輸出檔名
const char *preset = NULL;
const char *tune = NULL;
const char *profile = NULL;
if (argc <= 1)
{
x265_log(NULL, X265_LOG_ERROR, "No input file. Run x265 --help for a list of options.\n");
return true;
}
/* Presets are applied before all other options. */
for (optind = 0;; )
{
int c = getopt_long(argc, argv, short_options, long_options, NULL);
if (c == -1) // 選項結束或錯誤,退出迴圈
break;
else if (c == 'p')
preset = optarg;
else if (c == 't')
tune = optarg;
else if (c == 'D')
outputBitDepth = atoi(optarg);
else if (c == 'P')
profile = optarg;
else if (c == '?')
bShowHelp = true;
}
if (!outputBitDepth && profile)
{
/* try to derive the output bit depth from the requested profile */
if (strstr(profile, "10"))
outputBitDepth = 10;
else if (strstr(profile, "12"))
outputBitDepth = 12;
else
outputBitDepth = 8;
}
api = x265_api_get(outputBitDepth);
if (!api)
{
x265_log(NULL, X265_LOG_WARNING, "falling back to default bit-depth\n");
api = x265_api_get(0);
}
param = api->param_alloc();
if (!param)
{
x265_log(NULL, X265_LOG_ERROR, "param alloc failed\n");
return true;
}
if (api->param_default_preset(param, preset, tune) < 0)
{
x265_log(NULL, X265_LOG_ERROR, "preset or tune unrecognized\n");
return true;
}
if (bShowHelp)
{
printVersion(param, api);
showHelp(param);
}
for (optind = 0;; )
{
int long_options_index = -1;
int c = getopt_long(argc, argv, short_options, long_options, &long_options_index);
if (c == -1)
break;
switch (c)
{
case 'h':
printVersion(param, api);
showHelp(param);
break;
case 'V':
printVersion(param, api);
x265_report_simd(param);
exit(0);
default:
if (long_options_index < 0 && c > 0)
{
for (size_t i = 0; i < sizeof(long_options) / sizeof(long_options[0]); i++)
{
if (long_options[i].val == c)
{
long_options_index = (int)i;
break;
}
}
if (long_options_index < 0)
{
/* getopt_long might have already printed an error message */
if (c != 63)
x265_log(NULL, X265_LOG_WARNING, "internal error: short option '%c' has no long option\n", c);
return true;
}
}
... ...
}
... ...
}