YUV数据的复制

YUV数据的复制，详见：https://www.pnpon.com/article/detail-712.html

static void copy_frame_data(struct obs_source_frame *dst,
                const struct obs_source_frame *src)
{
    dst->flip = src->flip;
    dst->flags = src->flags;
    dst->trc = src->trc;
    dst->full_range = src->full_range;
    dst->max_luminance = src->max_luminance;
    dst->timestamp = src->timestamp;
    memcpy(dst->color_matrix, src->color_matrix, sizeof(float) * 16);
    if (!dst->full_range) {
        size_t const size = sizeof(float) * 3;
        memcpy(dst->color_range_min, src->color_range_min, size);
        memcpy(dst->color_range_max, src->color_range_max, size);
    }

    switch (src->format) {
    case VIDEO_FORMAT_I420:
    case VIDEO_FORMAT_I010: {
        const uint32_t height = dst->height;
        const uint32_t half_height = (height + 1) / 2;
        copy_frame_data_plane(dst, src, 0, height);
        copy_frame_data_plane(dst, src, 1, half_height);
        copy_frame_data_plane(dst, src, 2, half_height);
        break;
    }

    case VIDEO_FORMAT_NV12:
    case VIDEO_FORMAT_P010: {
        const uint32_t height = dst->height;
        const uint32_t half_height = (height + 1) / 2;
        copy_frame_data_plane(dst, src, 0, height);
        copy_frame_data_plane(dst, src, 1, half_height);
        break;
    }

    case VIDEO_FORMAT_I444:
    case VIDEO_FORMAT_I422:
    case VIDEO_FORMAT_I210:
    case VIDEO_FORMAT_I412:
        copy_frame_data_plane(dst, src, 0, dst->height);
        copy_frame_data_plane(dst, src, 1, dst->height);
        copy_frame_data_plane(dst, src, 2, dst->height);
        break;

    case VIDEO_FORMAT_YVYU:
    case VIDEO_FORMAT_YUY2:
    case VIDEO_FORMAT_UYVY:
    case VIDEO_FORMAT_NONE:
    case VIDEO_FORMAT_RGBA:
    case VIDEO_FORMAT_BGRA:
    case VIDEO_FORMAT_BGRX:
    case VIDEO_FORMAT_Y800:
    case VIDEO_FORMAT_BGR3:
    case VIDEO_FORMAT_AYUV:
    case VIDEO_FORMAT_V210:
    case VIDEO_FORMAT_R10L:
        copy_frame_data_plane(dst, src, 0, dst->height);
        break;

    case VIDEO_FORMAT_I40A: {
        const uint32_t height = dst->height;
        const uint32_t half_height = (height + 1) / 2;
        copy_frame_data_plane(dst, src, 0, height);
        copy_frame_data_plane(dst, src, 1, half_height);
        copy_frame_data_plane(dst, src, 2, half_height);
        copy_frame_data_plane(dst, src, 3, height);
        break;
    }

    case VIDEO_FORMAT_I42A:
    case VIDEO_FORMAT_YUVA:
    case VIDEO_FORMAT_YA2L:
        copy_frame_data_plane(dst, src, 0, dst->height);
        copy_frame_data_plane(dst, src, 1, dst->height);
        copy_frame_data_plane(dst, src, 2, dst->height);
        copy_frame_data_plane(dst, src, 3, dst->height);
        break;

    case VIDEO_FORMAT_P216:
    case VIDEO_FORMAT_P416:
        /* Unimplemented */
        break;
    }
}

关于数据的复制copy_frame_data_plane

static inline void copy_frame_data_line(struct obs_source_frame *dst,
                    const struct obs_source_frame *src,
                    uint32_t plane, uint32_t y)
{
    uint32_t pos_src = y * src->linesize[plane];//src起始位置
    uint32_t pos_dst = y * dst->linesize[plane];//dest起始位置
    uint32_t minbytes = dst->linesize[plane] < src->linesize[plane] //最小复制字节数
                 ? dst->linesize[plane]
                 : src->linesize[plane];

    memcpy(dst->data[plane] + pos_dst, src->data[plane] + pos_src, minbytes);
}

static inline void copy_frame_data_plane(struct obs_source_frame *dst,
                     const struct obs_source_frame *src,
                     uint32_t plane, uint32_t lines)
{
    //不等时，部分复制
    if (dst->linesize[plane] != src->linesize[plane])
    {
        for (uint32_t y = 0; y < lines; y++)
            copy_frame_data_line(dst, src, plane, y);
    } 
    else
    {
    //相等时直接整体复制
        memcpy(dst->data[plane], src->data[plane],(size_t)dst->linesize[plane] * (size_t)lines);
    }
}