Version 5.03 du 25/01/2003- New : Support for interlaced video in the decoder. Preserving the interlaced fields of interlaced video may sometimes result in better video quality during playback.
- New : New de-ringing post-processing algorithm. The new algorithm improves the perceived video quality during playback. It is activated when the post-processing level is set to Level 6.
- New : Video Buffer Verifier (VBV) model (one and two pass encoding). The VBV ensures that the maximum peak bit rate never exceeds either the user's inputted "maximum peak" bit rate value or/and ensures that the encoded stream never violates the buffer of an MPEG-4 compliant decoder. This helps to prevent decoding failure in both hardware and software where memory may be limited yet compliant to the MPEG-4 standard as defined in ISO/IEC 14496-2:2001(E). In order for DivX video to be successfully delivered over a restricted channel in real time to a decoder, the encoder's rate control must ensure that the decoder's buffer is not violated. When this is done properly, then overflow and underflow will never occur and the encoder is said to be "VBV compliant." It makes no difference whether the video is encoded in 1-pass or many, in real-time or offline. It is the encoder's rate control that must ensure compliance. There are three main requirements of a VBV-compliant rate control algorithm, in order of importance :
- - VBV compliance. When VBV parameters are specified (size, initial occupancy, channel characteristics) the rate control should avoid producing video that is in danger of violating the decoder's buffer. Bitstream stuffing may be used in extreme cases to prevent overflow in true CBR systems. Underflow must be prevented by increasing frame quantiser or by dropping frames.
- - Target bitrate. We aim to meet the user's requirements as accurately as possible here. This is directly related to filesize.
- - Good-looking video. Rate control should aim to produce the subjectively best quality video given other constraints. Consistency is important here as changes in quality are very noticeable and video is often judged by the worse quality segment in the whole sequence.
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