1 files changed, 114 insertions, 0 deletions
diff --git a/ffmpeg1/libavcodec/mpegaudio_parser.c b/ffmpeg1/libavcodec/mpegaudio_parser.c
new file mode 100644
index 0000000..4081936
--- /dev/null
+++ b/ffmpeg1/libavcodec/mpegaudio_parser.c
@@ -0,0 +1,114 @@
+/*
+ * MPEG Audio 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 "mpegaudiodecheader.h"
+#include "libavutil/common.h"
+
+
+typedef struct MpegAudioParseContext {
+    ParseContext pc;
+    int frame_size;
+    uint32_t header;
+    int header_count;
+    int no_bitrate;
+} MpegAudioParseContext;
+
+#define MPA_HEADER_SIZE 4
+
+/* header + layer + bitrate + freq + lsf/mpeg25 */
+#define SAME_HEADER_MASK \
+   (0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19))
+
+static int mpegaudio_parse(AVCodecParserContext *s1,
+                           AVCodecContext *avctx,
+                           const uint8_t **poutbuf, int *poutbuf_size,
+                           const uint8_t *buf, int buf_size)
+{
+    MpegAudioParseContext *s = s1->priv_data;
+    ParseContext *pc = &s->pc;
+    uint32_t state= pc->state;
+    int i;
+    int next= END_NOT_FOUND;
+
+    for(i=0; i<buf_size; ){
+        if(s->frame_size){
+            int inc= FFMIN(buf_size - i, s->frame_size);
+            i += inc;
+            s->frame_size -= inc;
+            state = 0;
+
+            if(!s->frame_size){
+                next= i;
+                break;
+            }
+        }else{
+            while(i<buf_size){
+                int ret, sr, channels, bit_rate, frame_size;
+
+                state= (state<<8) + buf[i++];
+
+                ret = avpriv_mpa_decode_header(avctx, state, &sr, &channels, &frame_size, &bit_rate);
+                if (ret < 4) {
+                    if (i > 4)
+                        s->header_count = -2;
+                } else {
+                    if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header)
+                        s->header_count= -3;
+                    s->header= state;
+                    s->header_count++;
+                    s->frame_size = ret-4;
+
+                    if (s->header_count > 0) {
+                        avctx->sample_rate= sr;
+                        avctx->channels   = channels;
+                        s1->duration      = frame_size;
+                        if (s->no_bitrate || !avctx->bit_rate) {
+                            s->no_bitrate = 1;
+                            avctx->bit_rate += (bit_rate - avctx->bit_rate) / s->header_count;
+                        }
+                    }
+                    break;
+                }
+            }
+        }
+    }
+
+    pc->state= state;
+    if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
+        *poutbuf = NULL;
+        *poutbuf_size = 0;
+        return buf_size;
+    }
+
+    *poutbuf = buf;
+    *poutbuf_size = buf_size;
+    return next;
+}
+
+
+AVCodecParser ff_mpegaudio_parser = {
+    .codec_ids      = { AV_CODEC_ID_MP1, AV_CODEC_ID_MP2, AV_CODEC_ID_MP3 },
+    .priv_data_size = sizeof(MpegAudioParseContext),
+    .parser_parse   = mpegaudio_parse,
+    .parser_close   = ff_parse_close,
+};