Method encodeData

plugins/VOIP/gui/VideoProcessor.cpp:371–430

}

bool JPEGVideo::encodeData(const QImage& image,uint32_t /* size_hint */,RsVOIPDataChunk& voip_chunk)
{
    // check if we make a diff image, or if we use the full frame.

    QImage encoded_frame ;
    bool differential_frame ;

    if (_encoded_ref_frame_count++ < _encoded_ref_frame_max_distance
        && image.size() == _encoded_reference_frame.size()
        && image.byteCount() == _encoded_reference_frame.byteCount())
	{
	    // compute difference with reference frame.
	    encoded_frame = image ;

	    for(int i=0;i<image.byteCount();++i)
	    {
		    // We cannot use basic modulo 256 arithmetic, because the decompressed JPeg frames do not follow the same rules (values are clamped)
		    // and cause color blotches when perturbated by a differential frame.

		    int diff = ( (int)image.bits()[i] - (int)_encoded_reference_frame.bits()[i]) + 128;
		    encoded_frame.bits()[i] = (unsigned char)std::max(0,std::min(255,diff)) ;
	    }

	    differential_frame = true ;
    }
    else
    {
	    _encoded_ref_frame_count = 0 ;
	    _encoded_reference_frame = image.copy() ;
	    encoded_frame = image ;

	    differential_frame = false ;
    }

    QByteArray qb ;

    QBuffer buffer(&qb) ;
    buffer.open(QIODevice::WriteOnly) ;
    encoded_frame.save(&buffer,"JPEG") ;

    voip_chunk.data = rs_malloc(HEADER_SIZE + qb.size());
    
    if(!voip_chunk.data)
        return false ;

    // build header
    uint32_t flags = differential_frame ? JPEG_VIDEO_FLAGS_DIFFERENTIAL_FRAME : 0x0 ;

    ((unsigned char *)voip_chunk.data)[0] =  VideoProcessor::VIDEO_PROCESSOR_CODEC_ID_JPEG_VIDEO       & 0xff ;
    ((unsigned char *)voip_chunk.data)[1] = (VideoProcessor::VIDEO_PROCESSOR_CODEC_ID_JPEG_VIDEO >> 8) & 0xff ;
    ((unsigned char *)voip_chunk.data)[2] = flags & 0xff ;
    ((unsigned char *)voip_chunk.data)[3] = (flags >> 8) & 0xff ;

    memcpy(&((unsigned char*)voip_chunk.data)[HEADER_SIZE],qb.data(),qb.size()) ;

    voip_chunk.size = HEADER_SIZE + qb.size() ;
    voip_chunk.type = RsVOIPDataChunk::RS_VOIP_DATA_TYPE_VIDEO ;