1/* 2 * Interface to libmp3lame for mp3 encoding 3 * Copyright (c) 2002 Lennert Buytenhek <buytenh@gnu.org> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file libavcodec/libmp3lame.c 24 * Interface to libmp3lame for mp3 encoding. 25 */ 26 27#include "avcodec.h" 28#include "mpegaudio.h" 29#include <lame/lame.h> 30 31#define BUFFER_SIZE (7200 + 2*MPA_FRAME_SIZE + MPA_FRAME_SIZE/4) 32typedef struct Mp3AudioContext { 33 lame_global_flags *gfp; 34 int stereo; 35 uint8_t buffer[BUFFER_SIZE]; 36 int buffer_index; 37} Mp3AudioContext; 38 39static av_cold int MP3lame_encode_init(AVCodecContext *avctx) 40{ 41 Mp3AudioContext *s = avctx->priv_data; 42 43 if (avctx->channels > 2) 44 return -1; 45 46 s->stereo = avctx->channels > 1 ? 1 : 0; 47 48 if ((s->gfp = lame_init()) == NULL) 49 goto err; 50 lame_set_in_samplerate(s->gfp, avctx->sample_rate); 51 lame_set_out_samplerate(s->gfp, avctx->sample_rate); 52 lame_set_num_channels(s->gfp, avctx->channels); 53 if(avctx->compression_level == FF_COMPRESSION_DEFAULT) { 54 lame_set_quality(s->gfp, 5); 55 } else { 56 lame_set_quality(s->gfp, avctx->compression_level); 57 } 58 /* lame 3.91 doesn't work in mono */ 59 lame_set_mode(s->gfp, JOINT_STEREO); 60 lame_set_brate(s->gfp, avctx->bit_rate/1000); 61 if(avctx->flags & CODEC_FLAG_QSCALE) { 62 lame_set_brate(s->gfp, 0); 63 lame_set_VBR(s->gfp, vbr_default); 64 lame_set_VBR_q(s->gfp, avctx->global_quality / (float)FF_QP2LAMBDA); 65 } 66 lame_set_bWriteVbrTag(s->gfp,0); 67 lame_set_disable_reservoir(s->gfp, avctx->flags2 & CODEC_FLAG2_BIT_RESERVOIR ? 0 : 1); 68 if (lame_init_params(s->gfp) < 0) 69 goto err_close; 70 71 avctx->frame_size = lame_get_framesize(s->gfp); 72 73 avctx->coded_frame= avcodec_alloc_frame(); 74 avctx->coded_frame->key_frame= 1; 75 76 return 0; 77 78err_close: 79 lame_close(s->gfp); 80err: 81 return -1; 82} 83 84static const int sSampleRates[3] = { 85 44100, 48000, 32000 86}; 87 88static const int sBitRates[2][3][15] = { 89 { { 0, 32, 64, 96,128,160,192,224,256,288,320,352,384,416,448}, 90 { 0, 32, 48, 56, 64, 80, 96,112,128,160,192,224,256,320,384}, 91 { 0, 32, 40, 48, 56, 64, 80, 96,112,128,160,192,224,256,320} 92 }, 93 { { 0, 32, 48, 56, 64, 80, 96,112,128,144,160,176,192,224,256}, 94 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160}, 95 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160} 96 }, 97}; 98 99static const int sSamplesPerFrame[2][3] = 100{ 101 { 384, 1152, 1152 }, 102 { 384, 1152, 576 } 103}; 104 105static const int sBitsPerSlot[3] = { 106 32, 107 8, 108 8 109}; 110 111static int mp3len(void *data, int *samplesPerFrame, int *sampleRate) 112{ 113 uint32_t header = AV_RB32(data); 114 int layerID = 3 - ((header >> 17) & 0x03); 115 int bitRateID = ((header >> 12) & 0x0f); 116 int sampleRateID = ((header >> 10) & 0x03); 117 int bitsPerSlot = sBitsPerSlot[layerID]; 118 int isPadded = ((header >> 9) & 0x01); 119 static int const mode_tab[4]= {2,3,1,0}; 120 int mode= mode_tab[(header >> 19) & 0x03]; 121 int mpeg_id= mode>0; 122 int temp0, temp1, bitRate; 123 124 if ( (( header >> 21 ) & 0x7ff) != 0x7ff || mode == 3 || layerID==3 || sampleRateID==3) { 125 return -1; 126 } 127 128 if(!samplesPerFrame) samplesPerFrame= &temp0; 129 if(!sampleRate ) sampleRate = &temp1; 130 131// *isMono = ((header >> 6) & 0x03) == 0x03; 132 133 *sampleRate = sSampleRates[sampleRateID]>>mode; 134 bitRate = sBitRates[mpeg_id][layerID][bitRateID] * 1000; 135 *samplesPerFrame = sSamplesPerFrame[mpeg_id][layerID]; 136//av_log(NULL, AV_LOG_DEBUG, "sr:%d br:%d spf:%d l:%d m:%d\n", *sampleRate, bitRate, *samplesPerFrame, layerID, mode); 137 138 return *samplesPerFrame * bitRate / (bitsPerSlot * *sampleRate) + isPadded; 139} 140 141static int MP3lame_encode_frame(AVCodecContext *avctx, 142 unsigned char *frame, int buf_size, void *data) 143{ 144 Mp3AudioContext *s = avctx->priv_data; 145 int len; 146 int lame_result; 147 148 /* lame 3.91 dies on '1-channel interleaved' data */ 149 150 if(data){ 151 if (s->stereo) { 152 lame_result = lame_encode_buffer_interleaved( 153 s->gfp, 154 data, 155 avctx->frame_size, 156 s->buffer + s->buffer_index, 157 BUFFER_SIZE - s->buffer_index 158 ); 159 } else { 160 lame_result = lame_encode_buffer( 161 s->gfp, 162 data, 163 data, 164 avctx->frame_size, 165 s->buffer + s->buffer_index, 166 BUFFER_SIZE - s->buffer_index 167 ); 168 } 169 }else{ 170 lame_result= lame_encode_flush( 171 s->gfp, 172 s->buffer + s->buffer_index, 173 BUFFER_SIZE - s->buffer_index 174 ); 175 } 176 177 if(lame_result < 0){ 178 if(lame_result==-1) { 179 /* output buffer too small */ 180 av_log(avctx, AV_LOG_ERROR, "lame: output buffer too small (buffer index: %d, free bytes: %d)\n", s->buffer_index, BUFFER_SIZE - s->buffer_index); 181 } 182 return -1; 183 } 184 185 s->buffer_index += lame_result; 186 187 if(s->buffer_index<4) 188 return 0; 189 190 len= mp3len(s->buffer, NULL, NULL); 191//av_log(avctx, AV_LOG_DEBUG, "in:%d packet-len:%d index:%d\n", avctx->frame_size, len, s->buffer_index); 192 if(len <= s->buffer_index){ 193 memcpy(frame, s->buffer, len); 194 s->buffer_index -= len; 195 196 memmove(s->buffer, s->buffer+len, s->buffer_index); 197 //FIXME fix the audio codec API, so we do not need the memcpy() 198/*for(i=0; i<len; i++){ 199 av_log(avctx, AV_LOG_DEBUG, "%2X ", frame[i]); 200}*/ 201 return len; 202 }else 203 return 0; 204} 205 206static av_cold int MP3lame_encode_close(AVCodecContext *avctx) 207{ 208 Mp3AudioContext *s = avctx->priv_data; 209 210 av_freep(&avctx->coded_frame); 211 212 lame_close(s->gfp); 213 return 0; 214} 215 216 217AVCodec libmp3lame_encoder = { 218 "libmp3lame", 219 CODEC_TYPE_AUDIO, 220 CODEC_ID_MP3, 221 sizeof(Mp3AudioContext), 222 MP3lame_encode_init, 223 MP3lame_encode_frame, 224 MP3lame_encode_close, 225 .capabilities= CODEC_CAP_DELAY, 226 .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE}, 227 .long_name= NULL_IF_CONFIG_SMALL("libmp3lame MP3 (MPEG audio layer 3)"), 228}; 229