From 54bfffcabc4601081f93b3196dc4b7406ac6ca6d Mon Sep 17 00:00:00 2001
From: skal <pascal.massimino@gmail.com>
Date: Wed, 14 May 2014 07:07:08 +0200
Subject: [PATCH] move RemapBitReader() from idec.c to bit_reader code

mostly for coherency and later patch.

Change-Id: Ica8352d67845b6c5b3153435edfb4646c6f24341
---
 src/dec/idec.c         | 11 ++---------
 src/utils/bit_reader.c |  7 +++++++
 src/utils/bit_reader.h |  4 ++++
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/dec/idec.c b/src/dec/idec.c
index 78208380..6e8d5985 100644
--- a/src/dec/idec.c
+++ b/src/dec/idec.c
@@ -86,13 +86,6 @@ typedef struct {
 //------------------------------------------------------------------------------
 // MemBuffer: incoming data handling
 
-static void RemapBitReader(VP8BitReader* const br, ptrdiff_t offset) {
-  if (br->buf_ != NULL) {
-    br->buf_ += offset;
-    br->buf_end_ += offset;
-  }
-}
-
 static WEBP_INLINE size_t MemDataSize(const MemBuffer* mem) {
   return (mem->end_ - mem->start_);
 }
@@ -129,12 +122,12 @@ static void DoRemap(WebPIDecoder* const idec, ptrdiff_t offset) {
       if (offset != 0) {
         int p;
         for (p = 0; p <= last_part; ++p) {
-          RemapBitReader(dec->parts_ + p, offset);
+          VP8RemapBitReader(dec->parts_ + p, offset);
         }
         // Remap partition #0 data pointer to new offset, but only in MAP
         // mode (in APPEND mode, partition #0 is copied into a fixed memory).
         if (mem->mode_ == MEM_MODE_MAP) {
-          RemapBitReader(&dec->br_, offset);
+          VP8RemapBitReader(&dec->br_, offset);
         }
       }
       assert(last_part >= 0);
diff --git a/src/utils/bit_reader.c b/src/utils/bit_reader.c
index 79f64d36..e236b687 100644
--- a/src/utils/bit_reader.c
+++ b/src/utils/bit_reader.c
@@ -35,6 +35,13 @@ void VP8InitBitReader(VP8BitReader* const br,
   br->eof_     = 0;
 }
 
+void VP8RemapBitReader(VP8BitReader* const br, ptrdiff_t offset) {
+  if (br->buf_ != NULL) {
+    br->buf_ += offset;
+    br->buf_end_ += offset;
+  }
+}
+
 const uint8_t kVP8Log2Range[128] = {
      7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
   3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
diff --git a/src/utils/bit_reader.h b/src/utils/bit_reader.h
index 02296796..7865e7b9 100644
--- a/src/utils/bit_reader.h
+++ b/src/utils/bit_reader.h
@@ -141,6 +141,10 @@ struct VP8BitReader {
 void VP8InitBitReader(VP8BitReader* const br,
                       const uint8_t* const start, const uint8_t* const end);
 
+// Update internal pointers to displace the byte buffer by the
+// relative offset 'offset'.
+void VP8RemapBitReader(VP8BitReader* const br, ptrdiff_t offset);
+
 // return the next value made of 'num_bits' bits
 uint32_t VP8GetValue(VP8BitReader* const br, int num_bits);
 static WEBP_INLINE uint32_t VP8Get(VP8BitReader* const br) {