From 3159780b18976dfd108576da473f4f97a9d7ca6f Mon Sep 17 00:00:00 2001
From: Justin Ruggles <justin.ruggles@gmail.com>
Date: Sat, 21 Mar 2009 00:44:42 +0000
Subject: [PATCH] share channel mode constants between the FLAC decoder and
 FLAC encoder

Originally committed as revision 18082 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/flac.h    |  7 +++++++
 libavcodec/flacdec.c | 25 +++++++++----------------
 libavcodec/flacenc.c | 14 ++++----------
 3 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/libavcodec/flac.h b/libavcodec/flac.h
index c957893d307..1e44a3b3941 100644
--- a/libavcodec/flac.h
+++ b/libavcodec/flac.h
@@ -34,6 +34,13 @@
 #define FLAC_MIN_BLOCKSIZE     16
 #define FLAC_MAX_BLOCKSIZE  65535
 
+enum {
+    FLAC_CHMODE_INDEPENDENT =  0,
+    FLAC_CHMODE_LEFT_SIDE   =  8,
+    FLAC_CHMODE_RIGHT_SIDE  =  9,
+    FLAC_CHMODE_MID_SIDE    = 10,
+};
+
 enum {
     FLAC_METADATA_TYPE_STREAMINFO = 0,
     FLAC_METADATA_TYPE_PADDING,
diff --git a/libavcodec/flacdec.c b/libavcodec/flacdec.c
index 7f2542a3019..2ef52617f38 100644
--- a/libavcodec/flacdec.c
+++ b/libavcodec/flacdec.c
@@ -46,13 +46,6 @@
 #undef NDEBUG
 #include <assert.h>
 
-enum decorrelation_type {
-    INDEPENDENT,
-    LEFT_SIDE,
-    RIGHT_SIDE,
-    MID_SIDE,
-};
-
 typedef struct FLACContext {
     FLACSTREAMINFO
 
@@ -63,7 +56,7 @@ typedef struct FLACContext {
     int curr_bps;                           ///< bps for current subframe, adjusted for channel correlation and wasted bits
     int sample_shift;                       ///< shift required to make output samples 16-bit or 32-bit
     int is32;                               ///< flag to indicate if output should be 32-bit instead of 16-bit
-    enum decorrelation_type decorrelation;  ///< channel decorrelation type in the current frame
+    int decorrelation;                      ///< channel decorrelation type in the current frame
     int got_streaminfo;                     ///< indicates if the STREAMINFO has been read
 
     int32_t *decoded[FLAC_MAX_CHANNELS];    ///< decoded samples
@@ -445,10 +438,10 @@ static inline int decode_subframe(FLACContext *s, int channel)
 
     s->curr_bps = s->bps;
     if (channel == 0) {
-        if (s->decorrelation == RIGHT_SIDE)
+        if (s->decorrelation == FLAC_CHMODE_RIGHT_SIDE)
             s->curr_bps++;
     } else {
-        if (s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
+        if (s->decorrelation == FLAC_CHMODE_LEFT_SIDE || s->decorrelation == FLAC_CHMODE_MID_SIDE)
             s->curr_bps++;
     }
 
@@ -508,9 +501,9 @@ static int decode_frame(FLACContext *s, int alloc_data_size)
 
     assignment = get_bits(&s->gb, 4); /* channel assignment */
     if (assignment < FLAC_MAX_CHANNELS && s->channels == assignment+1)
-        decorrelation = INDEPENDENT;
+        decorrelation = FLAC_CHMODE_INDEPENDENT;
     else if (assignment >= FLAC_MAX_CHANNELS && assignment < 11 && s->channels == 2)
-        decorrelation = LEFT_SIDE + assignment - 8;
+        decorrelation = assignment;
     else {
         av_log(s->avctx, AV_LOG_ERROR, "unsupported channel assignment %d (channels=%d)\n",
                assignment, s->channels);
@@ -710,7 +703,7 @@ static int flac_decode_frame(AVCodecContext *avctx,
             break;
 
     switch (s->decorrelation) {
-    case INDEPENDENT:
+    case FLAC_CHMODE_INDEPENDENT:
         for (j = 0; j < s->blocksize; j++) {
             for (i = 0; i < s->channels; i++) {
                 if (s->is32)
@@ -720,11 +713,11 @@ static int flac_decode_frame(AVCodecContext *avctx,
             }
         }
         break;
-    case LEFT_SIDE:
+    case FLAC_CHMODE_LEFT_SIDE:
         DECORRELATE(a,a-b)
-    case RIGHT_SIDE:
+    case FLAC_CHMODE_RIGHT_SIDE:
         DECORRELATE(a+b,b)
-    case MID_SIDE:
+    case FLAC_CHMODE_MID_SIDE:
         DECORRELATE( (a-=b>>1) + b, a)
     }
 
diff --git a/libavcodec/flacenc.c b/libavcodec/flacenc.c
index 7ddaf7ed814..1b2e52a3e6c 100644
--- a/libavcodec/flacenc.c
+++ b/libavcodec/flacenc.c
@@ -34,12 +34,6 @@
 #define FLAC_SUBFRAME_FIXED     8
 #define FLAC_SUBFRAME_LPC      32
 
-#define FLAC_CHMODE_NOT_STEREO      0
-#define FLAC_CHMODE_LEFT_RIGHT      1
-#define FLAC_CHMODE_LEFT_SIDE       8
-#define FLAC_CHMODE_RIGHT_SIDE      9
-#define FLAC_CHMODE_MID_SIDE       10
-
 #define MAX_FIXED_ORDER     4
 #define MAX_PARTITION_ORDER 8
 #define MAX_PARTITIONS     (1 << MAX_PARTITION_ORDER)
@@ -1006,7 +1000,7 @@ static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
         }
     }
     if(best == 0) {
-        return FLAC_CHMODE_LEFT_RIGHT;
+        return FLAC_CHMODE_INDEPENDENT;
     } else if(best == 1) {
         return FLAC_CHMODE_LEFT_SIDE;
     } else if(best == 2) {
@@ -1031,14 +1025,14 @@ static void channel_decorrelation(FlacEncodeContext *ctx)
     right = frame->subframes[1].samples;
 
     if(ctx->channels != 2) {
-        frame->ch_mode = FLAC_CHMODE_NOT_STEREO;
+        frame->ch_mode = FLAC_CHMODE_INDEPENDENT;
         return;
     }
 
     frame->ch_mode = estimate_stereo_mode(left, right, n);
 
     /* perform decorrelation and adjust bits-per-sample */
-    if(frame->ch_mode == FLAC_CHMODE_LEFT_RIGHT) {
+    if(frame->ch_mode == FLAC_CHMODE_INDEPENDENT) {
         return;
     }
     if(frame->ch_mode == FLAC_CHMODE_MID_SIDE) {
@@ -1078,7 +1072,7 @@ static void output_frame_header(FlacEncodeContext *s)
     put_bits(&s->pb, 16, 0xFFF8);
     put_bits(&s->pb, 4, frame->bs_code[0]);
     put_bits(&s->pb, 4, s->sr_code[0]);
-    if(frame->ch_mode == FLAC_CHMODE_NOT_STEREO) {
+    if(frame->ch_mode == FLAC_CHMODE_INDEPENDENT) {
         put_bits(&s->pb, 4, s->ch_code);
     } else {
         put_bits(&s->pb, 4, frame->ch_mode);
-- 
2.39.2