avcodec/g2meet, mjpegdec: Factor out common VLC initialization code

While just at it, remove the nb_codes parameter: It is redundant
(the number of codes is implicitly contained in the array containing how
many entries of a specific size there are) and for this reason it might
even be wrong, so it is better to check what is actually used instead.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

1 files changed, 9 insertions, 29 deletions

diff --git a/libavcodec/g2meet.c b/libavcodec/g2meet.c
index 70dc8c72a3..68b1b9dc74 100644
--- a/libavcodec/g2meet.c
+++ b/libavcodec/g2meet.c
@@ -41,6 +41,7 @@
 #include "internal.h"
 #include "jpegtables.h"
 #include "mjpeg.h"
+#include "mjpegdec.h"
 
 #define EPIC_PIX_STACK_SIZE 1024
 #define EPIC_PIX_STACK_MAX  (EPIC_PIX_STACK_SIZE - 1)
@@ -159,45 +160,24 @@ typedef struct G2MContext {
     int        cursor_hot_x, cursor_hot_y;
 } G2MContext;
 
-static av_cold int build_vlc(VLC *vlc, const uint8_t *bits_table,
-                             const uint8_t *val_table, int nb_codes,
-                             int is_ac)
-{
-    uint8_t  huff_size[256] = { 0 };
-    uint16_t huff_code[256];
-    uint16_t huff_sym[256];
-    int i;
-
-    ff_mjpeg_build_huffman_codes(huff_size, huff_code, bits_table, val_table);
-
-    for (i = 0; i < 256; i++)
-        huff_sym[i] = i + 16 * is_ac;
-
-    if (is_ac)
-        huff_sym[0] = 16 * 256;
-
-    return ff_init_vlc_sparse(vlc, 9, nb_codes, huff_size, 1, 1,
-                              huff_code, 2, 2, huff_sym, 2, 2, 0);
-}
-
 static av_cold int jpg_init(AVCodecContext *avctx, JPGContext *c)
 {
     int ret;
 
-    ret = build_vlc(&c->dc_vlc[0], avpriv_mjpeg_bits_dc_luminance,
-                    avpriv_mjpeg_val_dc, 12, 0);
+    ret = ff_mjpeg_build_vlc(&c->dc_vlc[0], avpriv_mjpeg_bits_dc_luminance,
+                             avpriv_mjpeg_val_dc, 0, avctx);
     if (ret)
         return ret;
-    ret = build_vlc(&c->dc_vlc[1], avpriv_mjpeg_bits_dc_chrominance,
-                    avpriv_mjpeg_val_dc, 12, 0);
+    ret = ff_mjpeg_build_vlc(&c->dc_vlc[1], avpriv_mjpeg_bits_dc_chrominance,
+                             avpriv_mjpeg_val_dc, 0, avctx);
     if (ret)
         return ret;
-    ret = build_vlc(&c->ac_vlc[0], avpriv_mjpeg_bits_ac_luminance,
-                    avpriv_mjpeg_val_ac_luminance, 251, 1);
+    ret = ff_mjpeg_build_vlc(&c->ac_vlc[0], avpriv_mjpeg_bits_ac_luminance,
+                             avpriv_mjpeg_val_ac_luminance, 1, avctx);
     if (ret)
         return ret;
-    ret = build_vlc(&c->ac_vlc[1], avpriv_mjpeg_bits_ac_chrominance,
-                    avpriv_mjpeg_val_ac_chrominance, 251, 1);
+    ret = ff_mjpeg_build_vlc(&c->ac_vlc[1], avpriv_mjpeg_bits_ac_chrominance,
+                             avpriv_mjpeg_val_ac_chrominance, 1, avctx);
     if (ret)
         return ret;