Method process_video_packet

src/FFmpegWriter.cpp:2063–2186

process video frame

// process video frame
void FFmpegWriter::process_video_packet(std::shared_ptr<Frame> frame) {
	// Source dimensions (RGBA)
	int src_w = frame->GetWidth();
	int src_h = frame->GetHeight();

	// Skip empty frames (1×1)
	if (src_w == 1 && src_h == 1)
		return;

	// Point persistent_src_frame->data to RGBA pixels
	const uchar* pixels = frame->GetPixels();
	if (!persistent_src_frame) {
		persistent_src_frame = av_frame_alloc();
		if (!persistent_src_frame)
			throw OutOfMemory("Could not allocate persistent_src_frame", path);
		persistent_src_frame->format      = AV_PIX_FMT_RGBA;
		persistent_src_frame->width       = src_w;
		persistent_src_frame->height      = src_h;
		persistent_src_frame->linesize[0] = src_w * 4;
	}
	persistent_src_frame->data[0] = const_cast<uint8_t*>(
		reinterpret_cast<const uint8_t*>(pixels)
	);

	// Prepare persistent_dst_frame + buffer on first use
	if (!persistent_dst_frame) {
		persistent_dst_frame = av_frame_alloc();
		if (!persistent_dst_frame)
			throw OutOfMemory("Could not allocate persistent_dst_frame", path);

		// Decide destination pixel format: NV12 if HW accel is on, else encoder’s pix_fmt
		AVPixelFormat dst_fmt = video_codec_ctx->pix_fmt;
#if USE_HW_ACCEL
		if (hw_en_on && hw_en_supported) {
			dst_fmt = AV_PIX_FMT_NV12;
		}
#endif
		persistent_dst_frame->format = dst_fmt;
		persistent_dst_frame->width  = info.width;
		persistent_dst_frame->height = info.height;

		persistent_dst_size = av_image_get_buffer_size(
			dst_fmt, info.width, info.height, 1
		);
		if (persistent_dst_size < 0)
			throw ErrorEncodingVideo("Invalid destination image size", -1);

		persistent_dst_buffer = static_cast<uint8_t*>(
			av_malloc(persistent_dst_size)
		);
		if (!persistent_dst_buffer)
			throw OutOfMemory("Could not allocate persistent_dst_buffer", path);

		av_image_fill_arrays(
			persistent_dst_frame->data,
			persistent_dst_frame->linesize,
			persistent_dst_buffer,
			dst_fmt,