2 * Interface to libmp3lame for mp3 encoding
3 * Copyright (c) 2002 Lennert Buytenhek <buytenh@gnu.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #include "mpegaudio.h"
23 #include <lame/lame.h>
25 typedef struct Mp3AudioContext {
26 lame_global_flags *gfp;
32 static int MP3lame_encode_init(AVCodecContext *avctx)
34 Mp3AudioContext *s = avctx->priv_data;
36 if (avctx->channels > 2)
40 s->stereo = avctx->channels > 1 ? 1 : 0;
42 if ((s->gfp = lame_init()) == NULL)
44 lame_set_in_samplerate(s->gfp, avctx->sample_rate);
45 lame_set_out_samplerate(s->gfp, avctx->sample_rate);
46 lame_set_num_channels(s->gfp, avctx->channels);
47 /* lame 3.91 dies on quality != 5 */
48 lame_set_quality(s->gfp, 5);
49 /* lame 3.91 doesn't work in mono */
50 lame_set_mode(s->gfp, JOINT_STEREO);
51 lame_set_brate(s->gfp, avctx->bit_rate/1000);
52 if (lame_init_params(s->gfp) < 0)
55 avctx->frame_size = MPA_FRAME_SIZE;
66 int MP3lame_encode_frame(AVCodecContext *avctx,
67 unsigned char *frame, int buf_size, void *data)
69 Mp3AudioContext *s = avctx->priv_data;
72 /* lame 3.91 dies on '1-channel interleaved' data */
74 num = lame_encode_buffer_interleaved(s->gfp, data,
75 MPA_FRAME_SIZE, frame, buf_size);
77 num = lame_encode_buffer(s->gfp, data, data, MPA_FRAME_SIZE,
81 /* lame 3.91 outputs the first frame as garbage */
83 s->first_frame = num = 0;
87 int MP3lame_encode_close(AVCodecContext *avctx)
89 Mp3AudioContext *s = avctx->priv_data;
96 AVCodec mp3lame_encoder = {
100 sizeof(Mp3AudioContext),
102 MP3lame_encode_frame,