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00027 #include "avcodec.h"
00028 #include "mpegaudio.h"
00029 #include <lame/lame.h>
00030
00031 #define BUFFER_SIZE (7200 + 2*MPA_FRAME_SIZE + MPA_FRAME_SIZE/4)
00032 typedef struct Mp3AudioContext {
00033 lame_global_flags *gfp;
00034 int stereo;
00035 uint8_t buffer[BUFFER_SIZE];
00036 int buffer_index;
00037 } Mp3AudioContext;
00038
00039 static av_cold int MP3lame_encode_init(AVCodecContext *avctx)
00040 {
00041 Mp3AudioContext *s = avctx->priv_data;
00042
00043 if (avctx->channels > 2)
00044 return -1;
00045
00046 s->stereo = avctx->channels > 1 ? 1 : 0;
00047
00048 if ((s->gfp = lame_init()) == NULL)
00049 goto err;
00050 lame_set_in_samplerate(s->gfp, avctx->sample_rate);
00051 lame_set_out_samplerate(s->gfp, avctx->sample_rate);
00052 lame_set_num_channels(s->gfp, avctx->channels);
00053 if(avctx->compression_level == FF_COMPRESSION_DEFAULT) {
00054 lame_set_quality(s->gfp, 5);
00055 } else {
00056 lame_set_quality(s->gfp, avctx->compression_level);
00057 }
00058 lame_set_mode(s->gfp, s->stereo ? JOINT_STEREO : MONO);
00059 lame_set_brate(s->gfp, avctx->bit_rate/1000);
00060 if(avctx->flags & CODEC_FLAG_QSCALE) {
00061 lame_set_brate(s->gfp, 0);
00062 lame_set_VBR(s->gfp, vbr_default);
00063 lame_set_VBR_quality(s->gfp, avctx->global_quality/(float)FF_QP2LAMBDA);
00064 }
00065 lame_set_bWriteVbrTag(s->gfp,0);
00066 lame_set_disable_reservoir(s->gfp, avctx->flags2 & CODEC_FLAG2_BIT_RESERVOIR ? 0 : 1);
00067 if (lame_init_params(s->gfp) < 0)
00068 goto err_close;
00069
00070 avctx->frame_size = lame_get_framesize(s->gfp);
00071
00072 avctx->coded_frame= avcodec_alloc_frame();
00073 avctx->coded_frame->key_frame= 1;
00074
00075 return 0;
00076
00077 err_close:
00078 lame_close(s->gfp);
00079 err:
00080 return -1;
00081 }
00082
00083 static const int sSampleRates[] = {
00084 44100, 48000, 32000, 22050, 24000, 16000, 11025, 12000, 8000, 0
00085 };
00086
00087 static const int sBitRates[2][3][15] = {
00088 { { 0, 32, 64, 96,128,160,192,224,256,288,320,352,384,416,448},
00089 { 0, 32, 48, 56, 64, 80, 96,112,128,160,192,224,256,320,384},
00090 { 0, 32, 40, 48, 56, 64, 80, 96,112,128,160,192,224,256,320}
00091 },
00092 { { 0, 32, 48, 56, 64, 80, 96,112,128,144,160,176,192,224,256},
00093 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160},
00094 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160}
00095 },
00096 };
00097
00098 static const int sSamplesPerFrame[2][3] =
00099 {
00100 { 384, 1152, 1152 },
00101 { 384, 1152, 576 }
00102 };
00103
00104 static const int sBitsPerSlot[3] = {
00105 32,
00106 8,
00107 8
00108 };
00109
00110 static int mp3len(void *data, int *samplesPerFrame, int *sampleRate)
00111 {
00112 uint32_t header = AV_RB32(data);
00113 int layerID = 3 - ((header >> 17) & 0x03);
00114 int bitRateID = ((header >> 12) & 0x0f);
00115 int sampleRateID = ((header >> 10) & 0x03);
00116 int bitsPerSlot = sBitsPerSlot[layerID];
00117 int isPadded = ((header >> 9) & 0x01);
00118 static int const mode_tab[4]= {2,3,1,0};
00119 int mode= mode_tab[(header >> 19) & 0x03];
00120 int mpeg_id= mode>0;
00121 int temp0, temp1, bitRate;
00122
00123 if ( (( header >> 21 ) & 0x7ff) != 0x7ff || mode == 3 || layerID==3 || sampleRateID==3) {
00124 return -1;
00125 }
00126
00127 if(!samplesPerFrame) samplesPerFrame= &temp0;
00128 if(!sampleRate ) sampleRate = &temp1;
00129
00130
00131
00132 *sampleRate = sSampleRates[sampleRateID]>>mode;
00133 bitRate = sBitRates[mpeg_id][layerID][bitRateID] * 1000;
00134 *samplesPerFrame = sSamplesPerFrame[mpeg_id][layerID];
00135
00136
00137 return *samplesPerFrame * bitRate / (bitsPerSlot * *sampleRate) + isPadded;
00138 }
00139
00140 static int MP3lame_encode_frame(AVCodecContext *avctx,
00141 unsigned char *frame, int buf_size, void *data)
00142 {
00143 Mp3AudioContext *s = avctx->priv_data;
00144 int len;
00145 int lame_result;
00146
00147
00148
00149 if(data){
00150 if (s->stereo) {
00151 lame_result = lame_encode_buffer_interleaved(
00152 s->gfp,
00153 data,
00154 avctx->frame_size,
00155 s->buffer + s->buffer_index,
00156 BUFFER_SIZE - s->buffer_index
00157 );
00158 } else {
00159 lame_result = lame_encode_buffer(
00160 s->gfp,
00161 data,
00162 data,
00163 avctx->frame_size,
00164 s->buffer + s->buffer_index,
00165 BUFFER_SIZE - s->buffer_index
00166 );
00167 }
00168 }else{
00169 lame_result= lame_encode_flush(
00170 s->gfp,
00171 s->buffer + s->buffer_index,
00172 BUFFER_SIZE - s->buffer_index
00173 );
00174 }
00175
00176 if(lame_result < 0){
00177 if(lame_result==-1) {
00178
00179 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);
00180 }
00181 return -1;
00182 }
00183
00184 s->buffer_index += lame_result;
00185
00186 if(s->buffer_index<4)
00187 return 0;
00188
00189 len= mp3len(s->buffer, NULL, NULL);
00190
00191 if(len <= s->buffer_index){
00192 memcpy(frame, s->buffer, len);
00193 s->buffer_index -= len;
00194
00195 memmove(s->buffer, s->buffer+len, s->buffer_index);
00196
00197
00198
00199
00200 return len;
00201 }else
00202 return 0;
00203 }
00204
00205 static av_cold int MP3lame_encode_close(AVCodecContext *avctx)
00206 {
00207 Mp3AudioContext *s = avctx->priv_data;
00208
00209 av_freep(&avctx->coded_frame);
00210
00211 lame_close(s->gfp);
00212 return 0;
00213 }
00214
00215
00216 AVCodec ff_libmp3lame_encoder = {
00217 "libmp3lame",
00218 AVMEDIA_TYPE_AUDIO,
00219 CODEC_ID_MP3,
00220 sizeof(Mp3AudioContext),
00221 MP3lame_encode_init,
00222 MP3lame_encode_frame,
00223 MP3lame_encode_close,
00224 .capabilities= CODEC_CAP_DELAY,
00225 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
00226 .supported_samplerates= sSampleRates,
00227 .long_name= NULL_IF_CONFIG_SMALL("libmp3lame MP3 (MPEG audio layer 3)"),
00228 };