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| author | Kostya Shishkov <kostya.shishkov@gmail.com> | 2020-04-03 11:58:57 +0200 |
|---|---|---|
| committer | Kostya Shishkov <kostya.shishkov@gmail.com> | 2020-04-03 11:58:57 +0200 |
| commit | 7f73eeeeff30f6319d5ff3fe6b945d64ce2c8fef (patch) | |
| tree | d92d383308173aa934a53083618d737a30575093 | |
| parent | 7588f4f2f381f948993daa01683d7a995e259c39 (diff) | |
| download | nihav-7f73eeeeff30f6319d5ff3fe6b945d64ce2c8fef.tar.gz | |
rv20: fix coefficient quantisation
| -rw-r--r-- | nihav-realmedia/src/codecs/rv20.rs | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/nihav-realmedia/src/codecs/rv20.rs b/nihav-realmedia/src/codecs/rv20.rs index d5415b6..7f24650 100644 --- a/nihav-realmedia/src/codecs/rv20.rs +++ b/nihav-realmedia/src/codecs/rv20.rs @@ -209,8 +209,8 @@ impl<'a> RealVideo20BR<'a> { }; let rl_cb = if sstate.is_iframe { &self.tables.aic_rl_cb } else { &self.tables.rl_cb }; - let q_add = if quant == 0 || sstate.is_iframe { 0i16 } else { ((quant - 1) | 1) as i16 }; - let q = if plane_no == 0 { (quant * 2) as i16 } else { H263_CHROMA_QUANT[quant as usize] as i16 }; + let q = if plane_no == 0 { (quant * 2) as i16 } else { (H263_CHROMA_QUANT[quant as usize] * 2) as i16 }; + let q_add = if q == 0 || sstate.is_iframe { 0i16 } else { (((q >> 1) - 1) | 1) as i16 }; while idx < 64 { let code = br.read_cb(rl_cb)?; let run; @@ -221,7 +221,11 @@ impl<'a> RealVideo20BR<'a> { level = code.get_level(); last = code.is_last(); if br.read_bool()? { level = -level; } - level = (level * q) + q_add; + if level >= 0 { + level = (level * q) + q_add; + } else { + level = (level * q) - q_add; + } } else { last = br.read_bool()?; run = br.read(6)? as u8; @@ -231,7 +235,11 @@ impl<'a> RealVideo20BR<'a> { let top = br.read_s(6)? as i16; level = (top << 5) | low; } - level = (level * q) + q_add; + if level >= 0 { + level = (level * q) + q_add; + } else { + level = (level * q) - q_add; + } if level < -2048 { level = -2048; } if level > 2047 { level = 2047; } } |