AVFrame can be interpreted as an AVPicture to fill the data
and linesize
fields. The easiest way to fill these field is to the use the avpicture_fill function.
To fill in the AVFrame's Y U and V buffers, it depends on your input data and what you want to do with the frame (do you want to write into the AVFrame and erase the initial data? or keep a copy).
If the buffer is large enough (at least linesize[0] * height
for Y data, linesize[1 or 2] * height/2
for U/V data), you can directly use input buffers:
// Initialize the AVFrame
AVFrame* frame = avcodec_alloc_frame();
frame->width = width;
frame->height = height;
frame->format = AV_PIX_FMT_YUV420P;
// Initialize frame->linesize
avpicture_fill((AVPicture*)frame, NULL, frame->format, frame->width, frame->height);
// Set frame->data pointers manually
frame->data[0] = inputBufferY;
frame->data[1] = inputBufferU;
frame->data[2] = inputBufferV;
// Or if your Y, U, V buffers are contiguous and have the correct size, simply use:
// avpicture_fill((AVPicture*)frame, inputBufferYUV, frame->format, frame->width, frame->height);
If you want/need to manipulate a copy of input data, you need to compute the needed buffer size, and copy input data in it.
// Initialize the AVFrame
AVFrame* frame = avcodec_alloc_frame();
frame->width = width;
frame->height = height;
frame->format = AV_PIX_FMT_YUV420P;
// Allocate a buffer large enough for all data
int size = avpicture_get_size(frame->format, frame->width, frame->height);
uint8_t* buffer = (uint8_t*)av_malloc(size);
// Initialize frame->linesize and frame->data pointers
avpicture_fill((AVPicture*)frame, buffer, frame->format, frame->width, frame->height);
// Copy data from the 3 input buffers
memcpy(frame->data[0], inputBufferY, frame->linesize[0] * frame->height);
memcpy(frame->data[1], inputBufferU, frame->linesize[1] * frame->height / 2);
memcpy(frame->data[2], inputBufferV, frame->linesize[2] * frame->height / 2);
Once you are done with the AVFrame, do not forget to free it with av_frame_free
(and any buffer allocated by av_malloc
).