From 6ba04c2b033942a66ee2af5fde67e091febd9aaa Mon Sep 17 00:00:00 2001
From: Aurelien Jacobs <aurel@gnuage.org>
Date: Sun, 13 May 2007 23:16:56 +0000
Subject: split jpeg_ls into jpeglsdec, jpeglsenc and jpegls

Originally committed as revision 9021 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/jpegls.h | 111 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 libavcodec/jpegls.h

(limited to 'libavcodec/jpegls.h')

diff --git a/libavcodec/jpegls.h b/libavcodec/jpegls.h
new file mode 100644
index 0000000000..2aba57ba63
--- /dev/null
+++ b/libavcodec/jpegls.h
@@ -0,0 +1,111 @@
+/*
+ * JPEG-LS common code
+ * Copyright (c) 2003 Michael Niedermayer
+ * Copyright (c) 2006 Konstantin Shishkov
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file jpegls.h
+ * JPEG-LS common code.
+ */
+
+#ifndef JPEGLS_H
+#define JPEGLS_H
+
+#include "avcodec.h"
+
+typedef struct JpeglsContext{
+    AVCodecContext *avctx;
+    AVFrame picture;
+}JpeglsContext;
+
+typedef struct JLSState{
+    int T1, T2, T3;
+    int A[367], B[367], C[365], N[367];
+    int limit, reset, bpp, qbpp, maxval, range;
+    int near, twonear;
+    int run_index[3];
+}JLSState;
+
+extern const uint8_t ff_log2_run[32];
+
+/**
+ * Calculate initial JPEG-LS parameters
+ */
+void ff_jpegls_init_state(JLSState *state);
+
+/**
+ * Calculate quantized gradient value, used for context determination
+ */
+static inline int ff_jpegls_quantize(JLSState *s, int v){ //FIXME optimize
+    if(v==0) return 0;
+    if(v < 0){
+        if(v <= -s->T3) return -4;
+        if(v <= -s->T2) return -3;
+        if(v <= -s->T1) return -2;
+        if(v <  -s->near) return -1;
+        return 0;
+    }else{
+        if(v <= s->near) return 0;
+        if(v <  s->T1) return 1;
+        if(v <  s->T2) return 2;
+        if(v <  s->T3) return 3;
+        return 4;
+    }
+}
+
+/**
+ * Calculate JPEG-LS codec values
+ */
+void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all);
+
+
+static inline void ff_jpegls_downscale_state(JLSState *state, int Q){
+    if(state->N[Q] == state->reset){
+        state->A[Q] >>=1;
+        state->B[Q] >>=1;
+        state->N[Q] >>=1;
+    }
+    state->N[Q]++;
+}
+
+static inline int ff_jpegls_update_state_regular(JLSState *state, int Q, int err){
+    state->A[Q] += FFABS(err);
+    err *= state->twonear;
+    state->B[Q] += err;
+
+    ff_jpegls_downscale_state(state, Q);
+
+    if(state->B[Q] <= -state->N[Q]) {
+        state->B[Q]= FFMAX(state->B[Q] + state->N[Q], 1-state->N[Q]);
+        if(state->C[Q] > -128)
+            state->C[Q]--;
+    }else if(state->B[Q] > 0){
+        state->B[Q]= FFMIN(state->B[Q] - state->N[Q], 0);
+        if(state->C[Q] < 127)
+            state->C[Q]++;
+    }
+
+    return err;
+}
+
+#define R(a, i   ) (bits == 8 ?  ((uint8_t*)(a))[i]    :  ((uint16_t*)(a))[i]  )
+#define W(a, i, v) (bits == 8 ? (((uint8_t*)(a))[i]=v) : (((uint16_t*)(a))[i]=v))
+
+#endif /* JPEGLS_H */
-- 
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