c++cx264libx264

encode x264(libx264) raw yuv frame data

I am trying to encode an MP4 video using raw YUV frames data, but I am not sure how can I fill the plane data (preferably without using other libraries like ffmpeg)

The frame data is already encoded in I420, and does not need conversion.

Here is what I am trying to do:

const char *frameData = /* Raw frame data */;

x264_t *encoder = x264_encoder_open(&param);
x264_picture_t imgInput, imgOutput;
x264_picture_alloc(&imgInput, X264_CSP_I420, width, height);

// how can I fill the struct data of imgInput

x264_nal_t *nals;
int i_nals;
int frameSize = x264_encoder_encode(encoder, &nals, &i_nals, &imgInput, &imgOutput);

The equivalent command line that I have found is : 

 x264 --output video.mp4 --fps 15 --input-res 1280x800 imgdata_01.raw

But I could not figure out how the app does it.

Thanks.

Solution

  • Look at libx264 API usage example. This example use fread() to fill frame allocated by x264_picture_alloc() with actual i420 data from stdin. If you already have i420 data in memory and want to skip memcpy step than instead of it you can:

    1. Use x264_picture_init() instead of x264_picture_alloc() and x264_picture_clean(). Because you don't need allocate memory on heap for frame data.
    2. Fill x264_picture_t.img struct fields: