2 * Interface to libmp3lame for mp3 encoding
3 * Copyright (c) 2002 Lennert Buytenhek <buytenh@gnu.org>
5 * This file is part of FFmpeg.
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.
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.
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
24 * Interface to libmp3lame for mp3 encoding.
28 #include "mpegaudio.h"
29 #include <lame/lame.h>
31 #define BUFFER_SIZE (7200 + 2*MPA_FRAME_SIZE + MPA_FRAME_SIZE/4)
32 typedef struct Mp3AudioContext {
33 lame_global_flags *gfp;
35 uint8_t buffer[BUFFER_SIZE];
39 static av_cold int MP3lame_encode_init(AVCodecContext *avctx)
41 Mp3AudioContext *s = avctx->priv_data;
43 if (avctx->channels > 2)
46 s->stereo = avctx->channels > 1 ? 1 : 0;
48 if ((s->gfp = lame_init()) == NULL)
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);
56 lame_set_quality(s->gfp, avctx->compression_level);
58 lame_set_mode(s->gfp, s->stereo ? JOINT_STEREO : MONO);
59 lame_set_brate(s->gfp, avctx->bit_rate/1000);
60 if(avctx->flags & CODEC_FLAG_QSCALE) {
61 lame_set_brate(s->gfp, 0);
62 lame_set_VBR(s->gfp, vbr_default);
63 lame_set_VBR_quality(s->gfp, avctx->global_quality/(float)FF_QP2LAMBDA);
65 lame_set_bWriteVbrTag(s->gfp,0);
66 lame_set_disable_reservoir(s->gfp, avctx->flags2 & CODEC_FLAG2_BIT_RESERVOIR ? 0 : 1);
67 if (lame_init_params(s->gfp) < 0)
70 avctx->frame_size = lame_get_framesize(s->gfp);
72 avctx->coded_frame= avcodec_alloc_frame();
73 avctx->coded_frame->key_frame= 1;
83 static const int sSampleRates[] = {
84 44100, 48000, 32000, 22050, 24000, 16000, 11025, 12000, 8000, 0
87 static const int sBitRates[2][3][15] = {
88 { { 0, 32, 64, 96,128,160,192,224,256,288,320,352,384,416,448},
89 { 0, 32, 48, 56, 64, 80, 96,112,128,160,192,224,256,320,384},
90 { 0, 32, 40, 48, 56, 64, 80, 96,112,128,160,192,224,256,320}
92 { { 0, 32, 48, 56, 64, 80, 96,112,128,144,160,176,192,224,256},
93 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160},
94 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160}
98 static const int sSamplesPerFrame[2][3] =
104 static const int sBitsPerSlot[3] = {
110 static int mp3len(void *data, int *samplesPerFrame, int *sampleRate)
112 uint32_t header = AV_RB32(data);
113 int layerID = 3 - ((header >> 17) & 0x03);
114 int bitRateID = ((header >> 12) & 0x0f);
115 int sampleRateID = ((header >> 10) & 0x03);
116 int bitsPerSlot = sBitsPerSlot[layerID];
117 int isPadded = ((header >> 9) & 0x01);
118 static int const mode_tab[4]= {2,3,1,0};
119 int mode= mode_tab[(header >> 19) & 0x03];
121 int temp0, temp1, bitRate;
123 if ( (( header >> 21 ) & 0x7ff) != 0x7ff || mode == 3 || layerID==3 || sampleRateID==3) {
127 if(!samplesPerFrame) samplesPerFrame= &temp0;
128 if(!sampleRate ) sampleRate = &temp1;
130 // *isMono = ((header >> 6) & 0x03) == 0x03;
132 *sampleRate = sSampleRates[sampleRateID]>>mode;
133 bitRate = sBitRates[mpeg_id][layerID][bitRateID] * 1000;
134 *samplesPerFrame = sSamplesPerFrame[mpeg_id][layerID];
135 //av_log(NULL, AV_LOG_DEBUG, "sr:%d br:%d spf:%d l:%d m:%d\n", *sampleRate, bitRate, *samplesPerFrame, layerID, mode);
137 return *samplesPerFrame * bitRate / (bitsPerSlot * *sampleRate) + isPadded;
140 static int MP3lame_encode_frame(AVCodecContext *avctx,
141 unsigned char *frame, int buf_size, void *data)
143 Mp3AudioContext *s = avctx->priv_data;
147 /* lame 3.91 dies on '1-channel interleaved' data */
151 lame_result = lame_encode_buffer_interleaved(
155 s->buffer + s->buffer_index,
156 BUFFER_SIZE - s->buffer_index
159 lame_result = lame_encode_buffer(
164 s->buffer + s->buffer_index,
165 BUFFER_SIZE - s->buffer_index
169 lame_result= lame_encode_flush(
171 s->buffer + s->buffer_index,
172 BUFFER_SIZE - s->buffer_index
177 if(lame_result==-1) {
178 /* output buffer too small */
179 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);
184 s->buffer_index += lame_result;
186 if(s->buffer_index<4)
189 len= mp3len(s->buffer, NULL, NULL);
190 //av_log(avctx, AV_LOG_DEBUG, "in:%d packet-len:%d index:%d\n", avctx->frame_size, len, s->buffer_index);
191 if(len <= s->buffer_index){
192 memcpy(frame, s->buffer, len);
193 s->buffer_index -= len;
195 memmove(s->buffer, s->buffer+len, s->buffer_index);
196 //FIXME fix the audio codec API, so we do not need the memcpy()
197 /*for(i=0; i<len; i++){
198 av_log(avctx, AV_LOG_DEBUG, "%2X ", frame[i]);
205 static av_cold int MP3lame_encode_close(AVCodecContext *avctx)
207 Mp3AudioContext *s = avctx->priv_data;
209 av_freep(&avctx->coded_frame);
216 AVCodec ff_libmp3lame_encoder = {
220 sizeof(Mp3AudioContext),
222 MP3lame_encode_frame,
223 MP3lame_encode_close,
224 .capabilities= CODEC_CAP_DELAY,
225 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
226 .supported_samplerates= sSampleRates,
227 .long_name= NULL_IF_CONFIG_SMALL("libmp3lame MP3 (MPEG audio layer 3)"),