AVCSequenceParameterSetReader

757class AVCSequenceParameterSetReader758{759	/**760	 * @var string761	 */762	public $sps;763	public $start = 0;764	public $currentBytes = 0;765	public $currentBits = 0;766 767	/**768	 * @var int769	 */770	public $width;771 772	/**773	 * @var int774	 */775	public $height;776 777	/**778	 * @param string $sps779	 */780	public function __construct($sps) {781		$this->sps = $sps;782	}783 784	public function readData() {785		$this->skipBits(8);786		$this->skipBits(8);787		$profile = $this->getBits(8);                               // read profile788		if ($profile > 0) {789			$this->skipBits(8);790			$level_idc = $this->getBits(8);                         // level_idc791			$this->expGolombUe();                                   // seq_parameter_set_id // sps792			$this->expGolombUe();                                   // log2_max_frame_num_minus4793			$picOrderType = $this->expGolombUe();                   // pic_order_cnt_type794			if ($picOrderType == 0) {795				$this->expGolombUe();                               // log2_max_pic_order_cnt_lsb_minus4796			} elseif ($picOrderType == 1) {797				$this->skipBits(1);                                 // delta_pic_order_always_zero_flag798				$this->expGolombSe();                               // offset_for_non_ref_pic799				$this->expGolombSe();                               // offset_for_top_to_bottom_field800				$num_ref_frames_in_pic_order_cnt_cycle = $this->expGolombUe(); // num_ref_frames_in_pic_order_cnt_cycle801				for ($i = 0; $i < $num_ref_frames_in_pic_order_cnt_cycle; $i++) {802					$this->expGolombSe();                           // offset_for_ref_frame[ i ]803				}804			}805			$this->expGolombUe();                                   // num_ref_frames806			$this->skipBits(1);                                     // gaps_in_frame_num_value_allowed_flag807			$pic_width_in_mbs_minus1 = $this->expGolombUe();        // pic_width_in_mbs_minus1808			$pic_height_in_map_units_minus1 = $this->expGolombUe(); // pic_height_in_map_units_minus1809 810			$frame_mbs_only_flag = $this->getBits(1);               // frame_mbs_only_flag811			if ($frame_mbs_only_flag == 0) {812				$this->skipBits(1);                                 // mb_adaptive_frame_field_flag813			}814			$this->skipBits(1);                                     // direct_8x8_inference_flag815			$frame_cropping_flag = $this->getBits(1);               // frame_cropping_flag816 817			$frame_crop_left_offset   = 0;818			$frame_crop_right_offset  = 0;819			$frame_crop_top_offset    = 0;820			$frame_crop_bottom_offset = 0;821 822			if ($frame_cropping_flag) {823				$frame_crop_left_offset   = $this->expGolombUe();   // frame_crop_left_offset824				$frame_crop_right_offset  = $this->expGolombUe();   // frame_crop_right_offset825				$frame_crop_top_offset    = $this->expGolombUe();   // frame_crop_top_offset826				$frame_crop_bottom_offset = $this->expGolombUe();   // frame_crop_bottom_offset827			}828			$this->skipBits(1);                                     // vui_parameters_present_flag829			// etc830 831			$this->width  = (($pic_width_in_mbs_minus1 + 1) * 16) - ($frame_crop_left_offset * 2) - ($frame_crop_right_offset * 2);832			$this->height = ((2 - $frame_mbs_only_flag) * ($pic_height_in_map_units_minus1 + 1) * 16) - ($frame_crop_top_offset * 2) - ($frame_crop_bottom_offset * 2);833		}834	}835 836	/**