From: Kostya Shishkov <kostya.shishkov@gmail.com>
Date: Thu, 4 Sep 2025 06:31:04 +0000 (+0200)
Subject: indeo2: support custom codes
X-Git-Url: https://git.nihav.org/?a=commitdiff_plain;h=30fa57652c8ebd12a33a62daf52db2f43eaae7b7;p=nihav.git

indeo2: support custom codes
---

diff --git a/nihav-indeo/src/codecs/indeo2.rs b/nihav-indeo/src/codecs/indeo2.rs
index ff17b54..80e4c8f 100644
--- a/nihav-indeo/src/codecs/indeo2.rs
+++ b/nihav-indeo/src/codecs/indeo2.rs
@@ -4,6 +4,27 @@ use nihav_core::formats;
 use nihav_core::codecs::*;
 use nihav_codec_support::codecs::HAMShuffler;
 
+const SYMS: [u8; 143] = [
+    0x01, 0x02, 0x81, 0x03, 0x04, 0x82, 0x05, 0x06,
+    0x83, 0x84, 0x07, 0x08, 0x85, 0x09, 0x0A, 0x0B,
+    0x0C, 0x0D, 0x0E, 0x86, 0x0F, 0x10, 0x87, 0x88,
+    0x11, 0x12, 0x13, 0x14, 0x89, 0x15, 0x16, 0x8A,
+    0x17, 0x18, 0x8B, 0x19, 0x1A, 0x8C, 0x1B, 0x1C,
+    0x8D, 0x1D, 0x1E, 0x8E, 0x1F, 0x20, 0x8F, 0x21,
+    0x22, 0x90, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
+    0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
+    0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38,
+    0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x40,
+    0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
+    0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
+    0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
+    0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60,
+    0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+    0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
+    0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
+    0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F
+];
+
 static INDEO2_DELTA_TABLE: [[u8; 256]; 4] = [
     [
       0x80, 0x80, 0x84, 0x84, 0x7C, 0x7C, 0x7F, 0x85,
@@ -173,6 +194,8 @@ static INDEO2_CODE_LENGTHS: &[u8] = &[
      5,  5,  5,  6,  6,  8,  8,  8,  8,  8,  9,  9,  9,  9,  9
 ];
 
+const DEF_ADD_BITS: [u8; 8] = [2, 3, 3, 4, 4, 4, 6, 6];
+
 struct IR2CodeReader { }
 
 impl CodebookDescReader<u8> for IR2CodeReader {
@@ -184,9 +207,32 @@ impl CodebookDescReader<u8> for IR2CodeReader {
     fn len(&mut self) -> usize { INDEO2_CODE_LENGTHS.len() }
 }
 
+fn make_codes(codes: &[u8; 8]) -> DecoderResult<Codebook<u8>> {
+    let mut cb_desc = Vec::with_capacity(SYMS.len());
+    let mut sym_no = 0;
+    let mut prefix = 0;
+    'codegen: for (i, &add_bits) in codes.iter().enumerate() {
+        let cur_bits = i as u8 + add_bits + 1;
+        let mut code = prefix << (add_bits + 1);
+        for _ in 0..(1 << add_bits) {
+            cb_desc.push(FullCodebookDesc { code: reverse_bits(code, cur_bits), bits: cur_bits, sym: SYMS[sym_no] });
+            sym_no += 1;
+            code += 1;
+            if sym_no >= SYMS.len() {
+                break 'codegen;
+            }
+        }
+        prefix = (prefix << 1) | 1;
+    }
+
+    let mut cb = FullCodebookDescReader::new(&cb_desc);
+    Ok(Codebook::new(&mut cb, CodebookMode::LSB)?)
+}
+
 struct Indeo2Decoder {
     info:    NACodecInfoRef,
     cb:      Codebook<u8>,
+    abits:   [u8; 8],
     frmmgr:  HAMShuffler<u8>,
     rtv2:    bool,
 }
@@ -197,7 +243,7 @@ impl Indeo2Decoder {
         let dummy_info = NACodecInfo::new_dummy();
         let mut coderead = IR2CodeReader{};
         let cb = Codebook::new(&mut coderead, CodebookMode::LSB).unwrap();
-        Indeo2Decoder { info: dummy_info, cb, frmmgr: HAMShuffler::new(), rtv2 }
+        Indeo2Decoder { info: dummy_info, cb, abits: DEF_ADD_BITS, frmmgr: HAMShuffler::new(), rtv2 }
     }
 
     fn decode_plane_intra(&self, br: &mut BitReader,
@@ -333,6 +379,14 @@ impl NADecoder for Indeo2Decoder {
         if src.len() <= IR2_START { return Err(DecoderError::ShortData); }
         let interframe = src[18];
         let tabs = src[34];
+
+        let mut cur_codes = [0; 8];
+        cur_codes.copy_from_slice(&src[40..48]);
+        if cur_codes != self.abits {
+            self.cb = make_codes(&cur_codes)?;
+            self.abits = cur_codes;
+        }
+
         let mut br = BitReader::new(&src[IR2_START..], BitReaderMode::LE);
         let luma_tab = tabs & 3;
         let chroma_tab = (tabs >> 2) & 3;