使用 x264 将 OpenGL 输出转换为 H264

Question

我想将 OpenGL 程序的输出转换为 h264 并流式传输输出。我在某处收集了大部分代码并得到了一个输出文件，但我不知道如何处理它，或者它是否有效。目前输出只是保存在 file.h264 中。

编辑：“全局”变量

    x264_param_t param;
    x264_t* encoder;
    x264_picture_t pic_in;
    x264_picture_t pic_out;

    x264_nal_t *headers;
    int i_nal;
    FILE* pFile;

我的初始化函数：

initX264() {
    pFile = fopen("file.h264", "wb");

    x264_param_t param;
    x264_param_default_preset(&param, "veryfast", "zerolatency");
    param.i_threads = 1;
    param.i_width = 1024;
    param.i_height = 768;
    param.i_fps_num = 30;
    param.i_fps_den = 1;

    param.i_keyint_max = 30;
    param.b_intra_refresh = 1;

    param.rc.i_rc_method = X264_RC_CRF;
    param.rc.f_rf_constant = 25;
    param.rc.f_rf_constant_max = 35;

    param.b_annexb = 0;
    param.b_repeat_headers = 0;

    param.i_log_level = X264_LOG_DEBUG;

    x264_param_apply_profile(&param, "baseline");

    encoder = x264_encoder_open(&param);
    x264_picture_alloc(&pic_in, X264_CSP_I420, 1024, 768);

    x264_encoder_parameters( encoder, &param );

    x264_encoder_headers( encoder, &headers, &i_nal );

    int size = headers[0].i_payload + headers[1].i_payload + headers[2].i_payload;
    fwrite( headers[0].p_payload, 1, size, pFile);
}

这进入渲染函数，每秒执行大约 30 次：

    GLubyte *data = new GLubyte[3 * 1024 * 768];
    GLubyte *PixelYUV = new GLubyte[3 * 1024 * 768];

    glReadPixels(0, 0, 1024, 768, GL_RGB, GL_UNSIGNED_BYTE, data);
    RGB2YUV(1024, 768, data, PixelYUV, PixelYUV + 1024 * 768, PixelYUV + 1024 * 768 + (1024 * 768) / 4, true);
    pic_in.img.plane[0] = PixelYUV;
    pic_in.img.plane[1] = PixelYUV + 1024 * 768;
    pic_in.img.plane[2] = PixelYUV + 1024 * 768 + (1024 * 768) / 4;

    x264_nal_t* nals;
    int i_nals;
    int frame_size = x264_encoder_encode(encoder, &nals, &i_nals, &pic_in, &pic_out);

    if( frame_size )
    {
        fwrite( (char*)nals[0].p_payload, frame_size, 1, pFile );

    }

我从http://svn.gnumonks.org/trunk/21c3-video/cutting_tagging/tools/mpeg4ip-1.2/server/util/rgb2yuv/rgb2yuv.c 获得了 GRB2YUV 功能

输出看起来像

x264 [debug]: frame=   0 QP=11.14 NAL=3 Slice:I Poc:0   I:3072 P:0    SKIP:0    size=21133 bytes
x264 [debug]: frame=   1 QP=20.08 NAL=2 Slice:P Poc:2   I:0    P:14   SKIP:3058 size=72 bytes
x264 [debug]: frame=   2 QP=18.66 NAL=2 Slice:P Poc:4   I:0    P:48   SKIP:3024 size=161 bytes
x264 [debug]: frame=   3 QP=18.23 NAL=2 Slice:P Poc:6   I:0    P:84   SKIP:2988 size=293 bytes

在 Linux 文件 file.h264 上返回数据。

Answer 1

 X264 expects YUV420P data (I guess some others also, but that's the common one). You can use libswscale (from ffmpeg) to convert images to the right format. Initializing this is like this (i assume RGB data with 24bpp).

这很可能是您收不到任何可用视频的原因。你可以在这里找到更多关于做什么：How does one encode a series of images into H264 using the x264 C API?

缩放：

 sws_scale(convertCtx, &data, &srcstride, 0, h, pic_in.img.plane, pic_in.img.stride);
 //pic_in is your RGB data getting fed to scale. 

Answer 2

您的文件格式不正确。什么都无法阅读。 A .264 使用在 IDR 帧前附加标头的附件 B。

更改这些参数，

param.b_annexb = 1;
param.b_repeat_headers = 1;

然后删除

x264_encoder_headers( encoder, &headers, &i_nal );
int size = headers[0].i_payload + headers[1].i_payload + headers[2].i_payload;
fwrite( headers[0].p_payload, 1, size, pFile);

最后，您应该能够获取您的输出并将其转换为 mp4。

ffmpeg -i file.264 -vcodec copy -an file.mp4