📄 libamr.c
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/* * AMR Audio decoder stub * Copyright (c) 2003 the ffmpeg project * * 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 */ /** @file * Adaptive Multi-Rate (AMR) Audio decoder stub. * * This code implements both an AMR-NarrowBand (AMR-NB) and an AMR-WideBand * (AMR-WB) audio encoder/decoder through external reference code from * http://www.3gpp.org/. The license of the code from 3gpp is unclear so you * have to download the code separately. Two versions exists: One fixed-point * and one floating-point. For some reason the float encoder is significantly * faster at least on a P4 1.5GHz (0.9s instead of 9.9s on a 30s audio clip * at MR102). Both float and fixed point are supported for AMR-NB, but only * float for AMR-WB. * * \section AMR-NB * * \subsection Float * The float version (default) can be downloaded from: * http://www.3gpp.org/ftp/Specs/archive/26_series/26.104/26104-610.zip * * \subsection Fixed-point * The fixed-point (TS26.073) can be downloaded from: * http://www.3gpp.org/ftp/Specs/archive/26_series/26.073/26073-600.zip * * \subsection Specification * The specification for AMR-NB can be found in TS 26.071 * (http://www.3gpp.org/ftp/Specs/html-info/26071.htm) and some other * info at http://www.3gpp.org/ftp/Specs/html-info/26-series.htm. * * \section AMR-WB * * \subsection Float * The reference code can be downloaded from: * http://www.3gpp.org/ftp/Specs/archive/26_series/26.204/26204-600.zip * * \subsection Fixed-point * If someone wants to use the fixed point version it can be downloaded from: * http://www.3gpp.org/ftp/Specs/archive/26_series/26.173/26173-571.zip. * * \subsection Specification * The specification for AMR-WB can be found in TS 26.171 * (http://www.3gpp.org/ftp/Specs/html-info/26171.htm) and some other * info at http://www.3gpp.org/ftp/Specs/html-info/26-series.htm. * */#include "avcodec.h"#ifdef CONFIG_LIBAMR_NB_FIXED#define MMS_IO#include "amr/sp_dec.h"#include "amr/d_homing.h"#include "amr/typedef.h"#include "amr/sp_enc.h"#include "amr/sid_sync.h"#include "amr/e_homing.h"#else#include <amrnb/interf_dec.h>#include <amrnb/interf_enc.h>#endifstatic const char *nb_bitrate_unsupported = "bitrate not supported: use one of 4.75k, 5.15k, 5.9k, 6.7k, 7.4k, 7.95k, 10.2k or 12.2k\n";static const char *wb_bitrate_unsupported = "bitrate not supported: use one of 6.6k, 8.85k, 12.65k, 14.25k, 15.85k, 18.25k, 19.85k, 23.05k, or 23.85k\n";/* Common code for fixed and float version*/typedef struct AMR_bitrates{ int rate; enum Mode mode;} AMR_bitrates;/* Match desired bitrate */static int getBitrateMode(int bitrate){ /* make the correspondance between bitrate and mode */#ifdef __CW32__ AMR_bitrates rates[8];#else AMR_bitrates rates[]={ {4750,MR475}, {5150,MR515}, {5900,MR59}, {6700,MR67}, {7400,MR74}, {7950,MR795}, {10200,MR102}, {12200,MR122}, };#endif int i; for(i=0;i<8;i++) { if(rates[i].rate==bitrate) { return rates[i].mode; } } /* no bitrate matching, return an error */ return -1;}static void amr_decode_fix_avctx(AVCodecContext * avctx){ const int is_amr_wb = 1 + (avctx->codec_id == CODEC_ID_AMR_WB); if(avctx->sample_rate == 0) { avctx->sample_rate = 8000 * is_amr_wb; } if(avctx->channels == 0) { avctx->channels = 1; } avctx->frame_size = 160 * is_amr_wb;}#ifdef CONFIG_LIBAMR_NB_FIXED/* fixed point version*//* frame size in serial bitstream file (frame type + serial stream + flags) */#define SERIAL_FRAMESIZE (1+MAX_SERIAL_SIZE+5)typedef struct AMRContext { int frameCount; Speech_Decode_FrameState *speech_decoder_state; enum RXFrameType rx_type; enum Mode mode; Word16 reset_flag; Word16 reset_flag_old; int enc_bitrate; Speech_Encode_FrameState *enstate; sid_syncState *sidstate; enum TXFrameType tx_frametype;} AMRContext;static int amr_nb_decode_init(AVCodecContext * avctx){ AMRContext *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")) { av_log(avctx, AV_LOG_ERROR, "Speech_Decode_Frame_init error\n"); return -1; } amr_decode_fix_avctx(avctx); if(avctx->channels > 1) { av_log(avctx, AV_LOG_ERROR, "amr_nb: multichannel decoding not supported\n"); return -1; } return 0;}static int amr_nb_encode_init(AVCodecContext * avctx){ AMRContext *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(avctx->sample_rate!=8000) { av_log(avctx, AV_LOG_ERROR, "Only 8000Hz sample rate supported\n"); return -1; } if(avctx->channels!=1) { av_log(avctx, AV_LOG_ERROR, "Only mono supported\n"); return -1; } avctx->frame_size=160; avctx->coded_frame= avcodec_alloc_frame(); if(Speech_Encode_Frame_init(&s->enstate, 0, "encoder") || sid_sync_init (&s->sidstate)) { av_log(avctx, AV_LOG_ERROR, "Speech_Encode_Frame_init error\n"); return -1; } if((s->enc_bitrate=getBitrateMode(avctx->bit_rate))<0) { av_log(avctx, AV_LOG_ERROR, nb_bitrate_unsupported); return -1; } return 0;}static int amr_nb_encode_close(AVCodecContext * avctx){ AMRContext *s = avctx->priv_data; Speech_Encode_Frame_exit(&s->enstate); sid_sync_exit (&s->sidstate); av_freep(&avctx->coded_frame); return 0;}static int amr_nb_decode_close(AVCodecContext * avctx){ AMRContext *s = avctx->priv_data; Speech_Decode_Frame_exit(&s->speech_decoder_state); return 0;}static int amr_nb_decode_frame(AVCodecContext * avctx, void *data, int *data_size, uint8_t * buf, int buf_size){ AMRContext *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_size=%i buf=0x%X buf_size=%d frameCount=%d!!\n",*data_size,buf,buf_size,s->frameCount); synth=data; toc=amrData[offset]; /* read rest of the frame based on ToC byte */ q = (toc >> 2) & 0x01; ft = (toc >> 3) & 0x0F; //printf("offset=%d, packet_size=%d amrData= 0x%X %X %X %X\n",offset,packed_size[ft],amrData[offset],amrData[offset+1],amrData[offset+2],amrData[offset+3]); offset++; 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; /* 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 offset;}static int amr_nb_encode_frame(AVCodecContext *avctx, unsigned char *frame/*out*/, int buf_size, void *data/*in*/){ short serial_data[250] = {0}; AMRContext *s = avctx->priv_data; int written; s->reset_flag = encoder_homing_frame_test(data); Speech_Encode_Frame(s->enstate, s->enc_bitrate, data, &serial_data[1], &s->mode); /* add frame type and mode */ sid_sync (s->sidstate, s->mode, &s->tx_frametype); written = PackBits(s->mode, s->enc_bitrate, s->tx_frametype, &serial_data[1], frame); if (s->reset_flag != 0) { Speech_Encode_Frame_reset(s->enstate); sid_sync_reset(s->sidstate); } return written;}#elif defined(CONFIG_LIBAMR_NB) /* Float point version*/typedef struct AMRContext { int frameCount; void * decState; int *enstate; int enc_bitrate;} AMRContext;static int amr_nb_decode_init(AVCodecContext * avctx){ AMRContext *s = avctx->priv_data; s->frameCount=0; s->decState=Decoder_Interface_init(); if(!s->decState) { av_log(avctx, AV_LOG_ERROR, "Decoder_Interface_init error\r\n"); return -1; } amr_decode_fix_avctx(avctx); if(avctx->channels > 1)
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