huffman/huffyuv: move lorens huffman table generation code to huffman.c/h

Reviewed-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

configure

@@ -1557,6 +1557,7 @@ h264_vaapi_hwaccel_select="vaapi h264_decoder"
 h264_vda_hwaccel_deps="VideoDecodeAcceleration_VDADecoder_h pthreads"
 h264_vda_hwaccel_select="vda h264_decoder"
 h264_vdpau_decoder_select="vdpau h264_decoder"
+huffyuv_encoder_select="huffman"
 iac_decoder_select="fft mdct sinewin"
 imc_decoder_select="fft mdct sinewin"
 jpegls_decoder_select="golomb"

libavcodec/huffman.c

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2006 Konstantin Shishkov
+ * Copyright (c) 2007 Loren Merritt
  *
  * This file is part of FFmpeg.
  *
@@ -111,3 +112,60 @@ int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes,
     }
     return 0;
 }
+
+typedef struct {
+    uint64_t val;
+    int name;
+} HeapElem;
+
+static void heap_sift(HeapElem *h, int root, int size)
+{
+    while(root*2+1 < size) {
+        int child = root*2+1;
+        if(child < size-1 && h[child].val > h[child+1].val)
+            child++;
+        if(h[root].val > h[child].val) {
+            FFSWAP(HeapElem, h[root], h[child]);
+            root = child;
+        } else
+            break;
+    }
+}
+
+void ff_generate_len_table(uint8_t *dst, const uint64_t *stats){
+    HeapElem h[256];
+    int up[2*256];
+    int len[2*256];
+    int offset, i, next;
+    int size = 256;
+
+    for(offset=1; ; offset<<=1){
+        for(i=0; i<size; i++){
+            h[i].name = i;
+            h[i].val = (stats[i] << 8) + offset;
+        }
+        for(i=size/2-1; i>=0; i--)
+            heap_sift(h, i, size);
+
+        for(next=size; next<size*2-1; next++){
+            // merge the two smallest entries, and put it back in the heap
+            uint64_t min1v = h[0].val;
+            up[h[0].name] = next;
+            h[0].val = INT64_MAX;
+            heap_sift(h, 0, size);
+            up[h[0].name] = next;
+            h[0].name = next;
+            h[0].val += min1v;
+            heap_sift(h, 0, size);
+        }
+
+        len[2*size-2] = 0;
+        for(i=2*size-3; i>=size; i--)
+            len[i] = len[up[i]] + 1;
+        for(i=0; i<size; i++) {
+            dst[i] = len[up[i]] + 1;
+            if(dst[i] >= 32) break;
+        }
+        if(i==size) break;
+    }
+}

libavcodec/huffman.h

@@ -42,4 +42,6 @@ typedef int (*HuffCmp)(const void *va, const void *vb);
 int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes,
                        Node *nodes, HuffCmp cmp, int flags);
 
+void ff_generate_len_table(uint8_t *dst, const uint64_t *stats);
+
 #endif /* AVCODEC_HUFFMAN_H */

libavcodec/huffyuv.c

@@ -34,6 +34,7 @@
 #include "put_bits.h"
 #include "dsputil.h"
 #include "thread.h"
+#include "huffman.h"
 
 #define VLC_BITS 11
 
@@ -245,65 +246,6 @@ static int generate_bits_table(uint32_t *dst, const uint8_t *len_table){
     return 0;
 }
 
-#if CONFIG_HUFFYUV_ENCODER || CONFIG_FFVHUFF_ENCODER
-typedef struct {
-    uint64_t val;
-    int name;
-} HeapElem;
-
-static void heap_sift(HeapElem *h, int root, int size)
-{
-    while(root*2+1 < size) {
-        int child = root*2+1;
-        if(child < size-1 && h[child].val > h[child+1].val)
-            child++;
-        if(h[root].val > h[child].val) {
-            FFSWAP(HeapElem, h[root], h[child]);
-            root = child;
-        } else
-            break;
-    }
-}
-
-static void generate_len_table(uint8_t *dst, const uint64_t *stats){
-    HeapElem h[256];
-    int up[2*256];
-    int len[2*256];
-    int offset, i, next;
-    int size = 256;
-
-    for(offset=1; ; offset<<=1){
-        for(i=0; i<size; i++){
-            h[i].name = i;
-            h[i].val = (stats[i] << 8) + offset;
-        }
-        for(i=size/2-1; i>=0; i--)
-            heap_sift(h, i, size);
-
-        for(next=size; next<size*2-1; next++){
-            // merge the two smallest entries, and put it back in the heap
-            uint64_t min1v = h[0].val;
-            up[h[0].name] = next;
-            h[0].val = INT64_MAX;
-            heap_sift(h, 0, size);
-            up[h[0].name] = next;
-            h[0].name = next;
-            h[0].val += min1v;
-            heap_sift(h, 0, size);
-        }
-
-        len[2*size-2] = 0;
-        for(i=2*size-3; i>=size; i--)
-            len[i] = len[up[i]] + 1;
-        for(i=0; i<size; i++) {
-            dst[i] = len[up[i]] + 1;
-            if(dst[i] >= 32) break;
-        }
-        if(i==size) break;
-    }
-}
-#endif /* CONFIG_HUFFYUV_ENCODER || CONFIG_FFVHUFF_ENCODER */
-
 static void generate_joint_tables(HYuvContext *s){
     uint16_t symbols[1<<VLC_BITS];
     uint16_t bits[1<<VLC_BITS];
@@ -704,7 +646,7 @@ static av_cold int encode_init(AVCodecContext *avctx)
     }
 
     for(i=0; i<3; i++){
-        generate_len_table(s->len[i], s->stats[i]);
+        ff_generate_len_table(s->len[i], s->stats[i]);
 
         if(generate_bits_table(s->bits[i], s->len[i])<0){
             return -1;
@@ -1290,7 +1232,7 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
 
     if(s->context){
         for(i=0; i<3; i++){
-            generate_len_table(s->len[i], s->stats[i]);
+            ff_generate_len_table(s->len[i], s->stats[i]);
             if(generate_bits_table(s->bits[i], s->len[i])<0)
                 return -1;
             size += store_table(s, s->len[i], &pkt->data[size]);