projects / libav.git / blame
| Commit | Line | Data |
|---|---|---|
| 0716b577 J |
1 | /* |
| 2 | * Interface to libmp3lame for mp3 encoding | |
| 3 | * Copyright (c) 2002 Lennert Buytenhek <buytenh@gnu.org> | |
| 4 | * | |
| 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. | |
| 9 | * | |
| 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. | |
| 14 | * | |
| 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. | |
| 18 | */ | |
| 19 | ||
| 20 | #include "avcodec.h" | |
| 21 | #include <math.h> | |
| 22 | #include "mpegaudio.h" | |
| 23 | #include <lame/lame.h> | |
| 24 | ||
| 25 | typedef struct Mp3AudioContext { | |
| 26 | lame_global_flags *gfp; | |
| 27 | int first_frame; | |
| 28 | int stereo; | |
| 29 | } Mp3AudioContext; | |
| 30 | ||
| 31 | ||
| 32 | static int MP3lame_encode_init(AVCodecContext *avctx) | |
| 33 | { | |
| 34 | Mp3AudioContext *s = avctx->priv_data; | |
| 35 | ||
| 36 | if (avctx->channels > 2) | |
| 37 | return -1; | |
| 38 | ||
| 39 | s->first_frame = 1; | |
| 40 | s->stereo = avctx->channels > 1 ? 1 : 0; | |
| 41 | ||
| 42 | if ((s->gfp = lame_init()) == NULL) | |
| 43 | goto err; | |
| 44 | lame_set_in_samplerate(s->gfp, avctx->sample_rate); | |
| 45 | lame_set_num_channels(s->gfp, avctx->channels); | |
| 46 | /* lame 3.91 dies on quality != 5 */ | |
| 47 | lame_set_quality(s->gfp, 5); | |
| 48 | /* lame 3.91 doesn't work in mono */ | |
| 49 | lame_set_mode(s->gfp, JOINT_STEREO); | |
| 50 | lame_set_brate(s->gfp, avctx->bit_rate/1000); | |
| 51 | if (lame_init_params(s->gfp) < 0) | |
| 52 | goto err_close; | |
| 53 | ||
| 54 | avctx->frame_size = MPA_FRAME_SIZE; | |
| 55 | avctx->key_frame = 1; | |
| 56 | ||
| 57 | return 0; | |
| 58 | ||
| 59 | err_close: | |
| 60 | lame_close(s->gfp); | |
| 61 | err: | |
| 62 | return -1; | |
| 63 | } | |
| 64 | ||
| 65 | int MP3lame_encode_frame(AVCodecContext *avctx, | |
| 66 | unsigned char *frame, int buf_size, void *data) | |
| 67 | { | |
| 68 | Mp3AudioContext *s = avctx->priv_data; | |
| 69 | int num; | |
| 70 | ||
| 71 | /* lame 3.91 dies on '1-channel interleaved' data */ | |
| 72 | if (s->stereo) { | |
| 73 | num = lame_encode_buffer_interleaved(s->gfp, data, | |
| 74 | MPA_FRAME_SIZE, frame, buf_size); | |
| 75 | } else { | |
| 76 | num = lame_encode_buffer(s->gfp, data, data, MPA_FRAME_SIZE, | |
| 77 | frame, buf_size); | |
| 78 | } | |
| 79 | ||
| 80 | /* lame 3.91 outputs the first frame as garbage */ | |
| 81 | if (s->first_frame) | |
| 82 | s->first_frame = num = 0; | |
| 83 | ||
| 84 | return num; | |
| 85 | } | |
| 86 | ||
| 87 | int MP3lame_encode_close(AVCodecContext *avctx) | |
| 88 | { | |
| 89 | Mp3AudioContext *s = avctx->priv_data; | |
| 90 | ||
| 91 | lame_close(s->gfp); | |
| 92 | return 0; | |
| 93 | } | |
| 94 | ||
| 95 | ||
| 96 | AVCodec mp3lame_encoder = { | |
| 97 | "mp3", | |
| 98 | CODEC_TYPE_AUDIO, | |
| 99 | CODEC_ID_MP3LAME, | |
| 100 | sizeof(Mp3AudioContext), | |
| 101 | MP3lame_encode_init, | |
| 102 | MP3lame_encode_frame, | |
| 103 | MP3lame_encode_close | |
| 104 | }; |