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/*
* 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,
};
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