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libtwolame.c
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1 /*
2  * Interface to libtwolame for mp2 encoding
3  * Copyright (c) 2012 Paul B Mahol
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
24  * Interface to libtwolame for mp2 encoding.
25  */
26 
27 #include <twolame.h>
28 
29 #include "libavutil/common.h"
30 #include "libavutil/opt.h"
31 
32 #include "avcodec.h"
33 #include "internal.h"
34 #include "mpegaudio.h"
35 
36 typedef struct TWOLAMEContext {
37  AVClass *class;
38  int mode;
39  int psymodel;
40  int energy;
41  int error_protection;
42  int copyright;
43  int original;
44  int verbosity;
45 
46  twolame_options *glopts;
47  int64_t next_pts;
48 } TWOLAMEContext;
49 
50 static av_cold int twolame_encode_close(AVCodecContext *avctx)
51 {
52  TWOLAMEContext *s = avctx->priv_data;
53  twolame_close(&s->glopts);
54  return 0;
55 }
56 
57 static av_cold int twolame_encode_init(AVCodecContext *avctx)
58 {
59  TWOLAMEContext *s = avctx->priv_data;
60  int ret;
61 
62  avctx->frame_size = TWOLAME_SAMPLES_PER_FRAME;
63  avctx->delay = 512 - 32 + 1;
64 
65  s->glopts = twolame_init();
66  if (!s->glopts)
67  return AVERROR(ENOMEM);
68 
69  twolame_set_verbosity(s->glopts, s->verbosity);
70  twolame_set_mode(s->glopts, s->mode);
71  twolame_set_psymodel(s->glopts, s->psymodel);
72  twolame_set_energy_levels(s->glopts, s->energy);
73  twolame_set_error_protection(s->glopts, s->error_protection);
74  twolame_set_copyright(s->glopts, s->copyright);
75  twolame_set_original(s->glopts, s->original);
76 
77  twolame_set_num_channels(s->glopts, avctx->channels);
78  twolame_set_in_samplerate(s->glopts, avctx->sample_rate);
79  twolame_set_out_samplerate(s->glopts, avctx->sample_rate);
80 
81  if (!avctx->bit_rate)
82  avctx->bit_rate = avctx->sample_rate < 28000 ? 160000 : 384000;
83 
84  if (avctx->flags & CODEC_FLAG_QSCALE || !avctx->bit_rate) {
85  twolame_set_VBR(s->glopts, TRUE);
86  twolame_set_VBR_level(s->glopts,
87  avctx->global_quality / (float) FF_QP2LAMBDA);
88  av_log(avctx, AV_LOG_WARNING,
89  "VBR in MP2 is a hack, use another codec that supports it.\n");
90  } else {
91  twolame_set_bitrate(s->glopts, avctx->bit_rate / 1000);
92  }
93 
94  ret = twolame_init_params(s->glopts);
95  if (ret) {
96  twolame_encode_close(avctx);
97  return AVERROR_UNKNOWN;
98  }
99 
100  return 0;
101 }
102 
103 static int twolame_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
104  const AVFrame *frame, int *got_packet_ptr)
105 {
106  TWOLAMEContext *s = avctx->priv_data;
107  int ret;
108 
109  if ((ret = ff_alloc_packet2(avctx, avpkt, MPA_MAX_CODED_FRAME_SIZE)) < 0)
110  return ret;
111 
112  if (frame) {
113  switch (avctx->sample_fmt) {
114  case AV_SAMPLE_FMT_FLT:
115  ret = twolame_encode_buffer_float32_interleaved(s->glopts,
116  (const float *)frame->data[0],
117  frame->nb_samples,
118  avpkt->data,
119  avpkt->size);
120  break;
121  case AV_SAMPLE_FMT_FLTP:
122  ret = twolame_encode_buffer_float32(s->glopts,
123  (const float *)frame->data[0],
124  (const float *)frame->data[1],
125  frame->nb_samples,
126  avpkt->data, avpkt->size);
127  break;
128  case AV_SAMPLE_FMT_S16:
129  ret = twolame_encode_buffer_interleaved(s->glopts,
130  (const short int *)frame->data[0],
131  frame->nb_samples,
132  avpkt->data, avpkt->size);
133  break;
134  case AV_SAMPLE_FMT_S16P:
135  ret = twolame_encode_buffer(s->glopts,
136  (const short int *)frame->data[0],
137  (const short int *)frame->data[1],
138  frame->nb_samples,
139  avpkt->data, avpkt->size);
140  break;
141  default:
142  av_log(avctx, AV_LOG_ERROR,
143  "Unsupported sample format %d.\n", avctx->sample_fmt);
144  return AVERROR_BUG;
145  }
146  } else {
147  ret = twolame_encode_flush(s->glopts, avpkt->data, avpkt->size);
148  }
149 
150  if (!ret) // no bytes written
151  return 0;
152  if (ret < 0) // twolame error
153  return AVERROR_UNKNOWN;
154 
155  avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
156  if (frame) {
157  if (frame->pts != AV_NOPTS_VALUE)
158  avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->delay);
159  } else {
160  avpkt->pts = s->next_pts;
161  }
162  // this is for setting pts for flushed packet(s).
163  if (avpkt->pts != AV_NOPTS_VALUE)
164  s->next_pts = avpkt->pts + avpkt->duration;
165 
166  av_shrink_packet(avpkt, ret);
167  *got_packet_ptr = 1;
168  return 0;
169 }
170 
171 #define OFFSET(x) offsetof(TWOLAMEContext, x)
172 #define AE AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
173 static const AVOption options[] = {
174  { "mode", "Mpeg Mode", OFFSET(mode), AV_OPT_TYPE_INT, { .i64 = TWOLAME_AUTO_MODE }, TWOLAME_AUTO_MODE, TWOLAME_MONO, AE, "mode"},
175  { "auto", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_AUTO_MODE }, 0, 0, AE, "mode" },
176  { "stereo", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_STEREO }, 0, 0, AE, "mode" },
177  { "joint_stereo", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_JOINT_STEREO }, 0, 0, AE, "mode" },
178  { "dual_channel", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_DUAL_CHANNEL }, 0, 0, AE, "mode" },
179  { "mono", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_MONO }, 0, 0, AE, "mode" },
180  { "psymodel", "Psychoacoustic Model", OFFSET(psymodel), AV_OPT_TYPE_INT, { .i64 = 3 }, -1, 4, AE},
181  { "energy_levels","enable energy levels", OFFSET(energy), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE},
182  { "error_protection","enable CRC error protection", OFFSET(error_protection), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE},
183  { "copyright", "set MPEG Audio Copyright flag", OFFSET(copyright), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE},
184  { "original", "set MPEG Audio Original flag", OFFSET(original), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE},
185  { "verbosity", "set library optput level (0-10)", OFFSET(verbosity), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 10, AE},
186  { NULL },
187 };
188 
189 static const AVClass twolame_class = {
190  .class_name = "libtwolame encoder",
191  .item_name = av_default_item_name,
192  .option = options,
193  .version = LIBAVUTIL_VERSION_INT,
194 };
195 
196 static const AVCodecDefault twolame_defaults[] = {
197  { "b", "0" },
198  { NULL },
199 };
200 
201 static const int twolame_samplerates[] = {
202  16000, 22050, 24000, 32000, 44100, 48000, 0
203 };
204 
205 AVCodec ff_libtwolame_encoder = {
206  .name = "libtwolame",
207  .long_name = NULL_IF_CONFIG_SMALL("libtwolame MP2 (MPEG audio layer 2)"),
208  .type = AVMEDIA_TYPE_AUDIO,
209  .id = AV_CODEC_ID_MP2,
210  .priv_data_size = sizeof(TWOLAMEContext),
211  .init = twolame_encode_init,
212  .encode2 = twolame_encode_frame,
213  .close = twolame_encode_close,
214  .capabilities = CODEC_CAP_DELAY,
215  .defaults = twolame_defaults,
216  .priv_class = &twolame_class,
217  .sample_fmts = (const enum AVSampleFormat[]) {
218  AV_SAMPLE_FMT_FLT,
219  AV_SAMPLE_FMT_FLTP,
220  AV_SAMPLE_FMT_S16,
221  AV_SAMPLE_FMT_S16P,
222  AV_SAMPLE_FMT_NONE
223  },
224  .channel_layouts = (const uint64_t[]) {
225  AV_CH_LAYOUT_MONO,
226  AV_CH_LAYOUT_STEREO,
227  0 },
228  .supported_samplerates = twolame_samplerates,
229 };
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