move aac and ac3 parsers in their own files

Originally committed as revision 8941 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 91 insertions, 0 deletions

diff --git a/libavcodec/aac_ac3_parser.c b/libavcodec/aac_ac3_parser.c
new file mode 100644
index 0000000000..4dcf3974f1
--- /dev/null
+++ b/libavcodec/aac_ac3_parser.c
@@ -0,0 +1,91 @@
+/*
+ * Common AAC and AC3 parser
+ * Copyright (c) 2003 Fabrice Bellard.
+ * Copyright (c) 2003 Michael Niedermayer.
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "parser.h"
+#include "aac_ac3_parser.h"
+
+int ac3_parse(AVCodecParserContext *s1,
+                     AVCodecContext *avctx,
+                     const uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size)
+{
+    AC3ParseContext *s = s1->priv_data;
+    const uint8_t *buf_ptr;
+    int len, sample_rate, bit_rate, channels, samples;
+
+    *poutbuf = NULL;
+    *poutbuf_size = 0;
+
+    buf_ptr = buf;
+    while (buf_size > 0) {
+        len = s->inbuf_ptr - s->inbuf;
+        if (s->frame_size == 0) {
+            /* no header seen : find one. We need at least s->header_size
+               bytes to parse it */
+            len = FFMIN(s->header_size - len, buf_size);
+
+            memcpy(s->inbuf_ptr, buf_ptr, len);
+            buf_ptr += len;
+            s->inbuf_ptr += len;
+            buf_size -= len;
+            if ((s->inbuf_ptr - s->inbuf) == s->header_size) {
+                len = s->sync(s->inbuf, &channels, &sample_rate, &bit_rate,
+                              &samples);
+                if (len == 0) {
+                    /* no sync found : move by one byte (inefficient, but simple!) */
+                    memmove(s->inbuf, s->inbuf + 1, s->header_size - 1);
+                    s->inbuf_ptr--;
+                } else {
+                    s->frame_size = len;
+                    /* update codec info */
+                    avctx->sample_rate = sample_rate;
+                    /* set channels,except if the user explicitly requests 1 or 2 channels, XXX/FIXME this is a bit ugly */
+                    if(avctx->codec_id == CODEC_ID_AC3){
+                        if(avctx->channels!=1 && avctx->channels!=2){
+                            avctx->channels = channels;
+                        }
+                    } else {
+                        avctx->channels = channels;
+                    }
+                    avctx->bit_rate = bit_rate;
+                    avctx->frame_size = samples;
+                }
+            }
+        } else {
+            len = FFMIN(s->frame_size - len, buf_size);
+
+            memcpy(s->inbuf_ptr, buf_ptr, len);
+            buf_ptr += len;
+            s->inbuf_ptr += len;
+            buf_size -= len;
+
+            if(s->inbuf_ptr - s->inbuf == s->frame_size){
+                *poutbuf = s->inbuf;
+                *poutbuf_size = s->frame_size;
+                s->inbuf_ptr = s->inbuf;
+                s->frame_size = 0;
+                break;
+            }
+        }
+    }
+    return buf_ptr - buf;
+}