AMR-NB audio support patch by (<joca at rixmail dot se>)

Originally committed as revision 1876 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 163 insertions, 0 deletions

diff --git a/libavcodec/amr.c b/libavcodec/amr.c
new file mode 100644
index 0000000000..ca3df7fabd
--- /dev/null
+++ b/libavcodec/amr.c
@@ -0,0 +1,163 @@
+/*
+ * AMR Audio decoder stub
+ * Copyright (c) 2003 the ffmpeg project
+ *
+ * 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 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
+ * Lesser General Public License for more details.
+ *
+ * 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
+ */
+//#define DEBUG
+#define MMS_IO
+#include "avcodec.h"
+
+#include "amr/sp_dec.h"
+#include "amr/d_homing.h"
+#include "amr/typedef.h"
+
+/* frame size in serial bitstream file (frame type + serial stream + flags) */
+#define SERIAL_FRAMESIZE (1+MAX_SERIAL_SIZE+5)
+
+typedef struct AMRDecodeContext {
+    int frameCount;
+    Speech_Decode_FrameState *speech_decoder_state;
+    enum RXFrameType rx_type;
+    enum Mode mode;
+    Word16 reset_flag;
+    Word16 reset_flag_old;
+
+} AMRDecodeContext;
+
+static int amr_nb_decode_init(AVCodecContext * avctx)
+{
+    AMRDecodeContext *s = avctx->priv_data;
+    s->frameCount=0;
+    s->speech_decoder_state=NULL;
+    s->rx_type = (enum RXFrameType)0;
+    s->mode= (enum Mode)0;
+    s->reset_flag=0;
+    s->reset_flag_old=1;
+    
+    if(Speech_Decode_Frame_init(&s->speech_decoder_state, "Decoder"))
+    {
+        printf("error\r\n");
+        return -1;
+    }
+    return 0;
+}
+
+static int amr_decode_close(AVCodecContext * avctx)
+{
+    AMRDecodeContext *s = avctx->priv_data;
+    Speech_Decode_Frame_exit(&s->speech_decoder_state);
+}
+
+static int amr_nb_decode_frame(AVCodecContext * avctx,
+            void *data, int *data_size,
+            uint8_t * buf, int buf_size)
+{
+    AMRDecodeContext *s = avctx->priv_data;
+
+    uint8_t*amrData=buf;
+    int offset=0;
+
+    UWord8 toc, q, ft;
+    
+    Word16 serial[SERIAL_FRAMESIZE];   /* coded bits */
+    Word16 *synth;
+    UWord8 *packed_bits;
+
+    static Word16 packed_size[16] = {12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0};
+    int i;
+
+    //printf("amr_decode_frame data=0x%X data_size=%i buf=0x%X buf_size=%d frameCount=%d!!\n",data,&data_size,buf,buf_size,s->frameCount);
+
+    synth=data;
+
+    while(offset<buf_size)
+    {
+        toc=amrData[offset++];
+        /* read rest of the frame based on ToC byte */
+        q  = (toc >> 2) & 0x01;
+        ft = (toc >> 3) & 0x0F;
+
+        packed_bits=amrData+offset;
+
+        offset+=packed_size[ft];
+
+		//Unsort and unpack bits
+        s->rx_type = UnpackBits(q, ft, packed_bits, &s->mode, &serial[1]);
+
+		//We have a new frame
+        s->frameCount++;
+
+        if (s->rx_type == RX_NO_DATA) 
+        {
+            s->mode = s->speech_decoder_state->prev_mode;
+        }
+        else {
+            s->speech_decoder_state->prev_mode = s->mode;
+        }
+        
+        /* if homed: check if this frame is another homing frame */
+        if (s->reset_flag_old == 1)
+        {
+            /* only check until end of first subframe */
+            s->reset_flag = decoder_homing_frame_test_first(&serial[1], s->mode);
+        }
+        /* produce encoder homing frame if homed & input=decoder homing frame */
+        if ((s->reset_flag != 0) && (s->reset_flag_old != 0))
+        {
+            for (i = 0; i < L_FRAME; i++)
+            {
+                synth[i] = EHF_MASK;
+            }
+        }
+        else
+        {     
+            /* decode frame */
+            Speech_Decode_Frame(s->speech_decoder_state, s->mode, &serial[1], s->rx_type, synth);
+        }
+
+		//Each AMR-frame results in 160 16-bit samples
+        *data_size+=160*2;
+        synth+=160;
+        
+        /* if not homed: check whether current frame is a homing frame */
+        if (s->reset_flag_old == 0)
+        {
+            /* check whole frame */
+            s->reset_flag = decoder_homing_frame_test(&serial[1], s->mode);
+        }
+        /* reset decoder if current frame is a homing frame */
+        if (s->reset_flag != 0)
+        {
+            Speech_Decode_Frame_reset(s->speech_decoder_state);
+        }
+        s->reset_flag_old = s->reset_flag;
+        
+    }
+    return buf_size;
+}
+
+AVCodec amr_nb_decoder =
+{
+    "amr_nb",
+    CODEC_TYPE_AUDIO,
+    CODEC_ID_AMR_NB,
+    sizeof(AMRDecodeContext),
+    amr_nb_decode_init,
+    NULL,
+    amr_decode_close,
+    amr_nb_decode_frame,
+};
+