simplify (d&a) and (d&~a) calculation, hint by skal

[ffmpeg] / libavcodec / ac3dec.c

diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index eade4fb6ae36866684e712a5d9fd70c6221a47bb..db7189ec7a4af4591f154b3efa5b20cc55fe4c52 100644 (file)
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -1,29 +1,37 @@
 /*
  * AC3 decoder
- * Copyright (c) 2001 Gerard Lantau.
+ * Copyright (c) 2001 Fabrice Bellard.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * This library 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 of the License, or (at your option) any later version.
  *
- * This program is distributed in the hope that it will be useful,
+ * This library 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 General Public License for more details.
+ * 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 General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
+
+/**
+ * @file ac3dec.c
+ * AC3 decoder.
+ */
+
+//#define DEBUG
+
 #include "avcodec.h"
 #include "libac3/ac3.h"
 
 /* currently, I use libac3 which is Copyright (C) Aaron Holtzman and
    released under the GPL license. I may reimplement it someday... */
 typedef struct AC3DecodeState {
-    UINT8 inbuf[4096]; /* input buffer */
-    UINT8 *inbuf_ptr;
+    uint8_t inbuf[4096]; /* input buffer */
+    uint8_t *inbuf_ptr;
     int frame_size;
     int flags;
     int channels;
@@ -53,7 +61,7 @@ static inline int blah (int32_t i)
        return i - 0x43c00000;
 }
 
-static inline void float_to_int (float * _f, INT16 * s16, int nchannels)
+static inline void float_to_int (float * _f, int16_t * s16, int nchannels)
 {
     int i, j, c;
     int32_t * f = (int32_t *) _f;      // XXX assumes IEEE float format
@@ -72,19 +80,18 @@ static inline void float_to_int (float * _f, INT16 * s16, int nchannels)
 
 static int ac3_decode_frame(AVCodecContext *avctx, 
                             void *data, int *data_size,
-                            UINT8 *buf, int buf_size)
+                            uint8_t *buf, int buf_size)
 {
     AC3DecodeState *s = avctx->priv_data;
-    UINT8 *buf_ptr;
+    uint8_t *buf_ptr;
     int flags, i, len;
     int sample_rate, bit_rate;
     short *out_samples = data;
     float level;
-    static int ac3_channels[8] = {
+    static const int ac3_channels[8] = {
        2, 1, 2, 3, 3, 4, 4, 5
     };
 
-    *data_size = 0;
     buf_ptr = buf;
     while (buf_size > 0) {
         len = s->inbuf_ptr - s->inbuf;
@@ -104,27 +111,27 @@ static int ac3_decode_frame(AVCodecContext *avctx,
                     memcpy(s->inbuf, s->inbuf + 1, HEADER_SIZE - 1);
                     s->inbuf_ptr--;
                 } else {
-                    s->frame_size = len;
+                   s->frame_size = len;
                     /* update codec info */
                     avctx->sample_rate = sample_rate;
                     s->channels = ac3_channels[s->flags & 7];
                     if (s->flags & AC3_LFE)
-                                   s->channels++;
-                               if (avctx->channels == 0)
-                                   /* No specific number of channel requested */
-                                   avctx->channels = s->channels;
-                               else if (s->channels < avctx->channels) {
-                                   fprintf(stderr, "libav: AC3 Source channels are less than specified: output to %d channels..\n", s->channels);
-                                   avctx->channels = s->channels;
-                           }
-                           avctx->bit_rate = bit_rate;
+                       s->channels++;
+                   if (avctx->channels == 0)
+                       /* No specific number of channel requested */
+                       avctx->channels = s->channels;
+                   else if (s->channels < avctx->channels) {
+                        av_log( avctx, AV_LOG_INFO, "ac3dec: AC3 Source channels are less than specified: output to %d channels.. (frmsize: %d)\n", s->channels, len);
+                       avctx->channels = s->channels;
+                   }
+                   avctx->bit_rate = bit_rate;
                 }
             }
         } else if (len < s->frame_size) {
             len = s->frame_size - len;
             if (len > buf_size)
                 len = buf_size;
-            
+
             memcpy(s->inbuf_ptr, buf_ptr, len);
             buf_ptr += len;
             s->inbuf_ptr += len;
@@ -151,7 +158,7 @@ static int ac3_decode_frame(AVCodecContext *avctx,
             }
             s->inbuf_ptr = s->inbuf;
             s->frame_size = 0;
-            *data_size = 6 * avctx->channels * 256 * sizeof(INT16);
+            *data_size = 6 * avctx->channels * 256 * sizeof(int16_t);
             break;
         }
     }