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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/opt.h"
30 #include "avcodec.h"
31 #include "internal.h"
32 #include "mpegaudio.h"
33 
34 typedef struct TWOLAMEContext {
35  AVClass *class;
36  int mode;
37  int psymodel;
38  int energy;
40  int copyright;
41  int original;
42 
43  twolame_options *glopts;
44  int64_t next_pts;
46 
48 {
49  TWOLAMEContext *s = avctx->priv_data;
50  twolame_close(&s->glopts);
51  return 0;
52 }
53 
55 {
56  TWOLAMEContext *s = avctx->priv_data;
57  int ret;
58 
59  avctx->frame_size = TWOLAME_SAMPLES_PER_FRAME;
60 
61  s->glopts = twolame_init();
62  if (!s->glopts)
63  return AVERROR(ENOMEM);
64 
65  twolame_set_verbosity(s->glopts, 0);
66  twolame_set_mode(s->glopts, s->mode);
67  twolame_set_psymodel(s->glopts, s->psymodel);
68  twolame_set_energy_levels(s->glopts, s->energy);
69  twolame_set_error_protection(s->glopts, s->error_protection);
70 
71  twolame_set_num_channels(s->glopts, avctx->channels);
72  twolame_set_in_samplerate(s->glopts, avctx->sample_rate);
73  twolame_set_out_samplerate(s->glopts, avctx->sample_rate);
74  if (avctx->flags & CODEC_FLAG_QSCALE || !avctx->bit_rate) {
75  twolame_set_VBR(s->glopts, TRUE);
76  twolame_set_VBR_level(s->glopts, avctx->global_quality);
77  av_log(avctx, AV_LOG_WARNING, "VBR mode is experimental!\n");
78  } else {
79  twolame_set_bitrate(s->glopts, avctx->bit_rate / 1000);
80  }
81 
82  if ((ret = twolame_init_params(s->glopts)))
83  goto error;
84 
85  return 0;
86 error:
87  twolame_encode_close(avctx);
88  return ret;
89 }
90 
91 static int twolame_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
92  const AVFrame *frame, int *got_packet_ptr)
93 {
94  TWOLAMEContext *s = avctx->priv_data;
95  int ret;
96 
97  if ((ret = ff_alloc_packet2(avctx, avpkt, MPA_MAX_CODED_FRAME_SIZE)) < 0)
98  return ret;
99 
100  if (frame) {
101  switch (avctx->sample_fmt) {
102  case AV_SAMPLE_FMT_FLT:
103  ret = twolame_encode_buffer_float32_interleaved(s->glopts,
104  frame->data[0],
105  frame->nb_samples,
106  avpkt->data, avpkt->size);
107  break;
108  case AV_SAMPLE_FMT_FLTP:
109  ret = twolame_encode_buffer_float32(s->glopts,
110  frame->data[0], frame->data[1],
111  frame->nb_samples,
112  avpkt->data, avpkt->size);
113  break;
114  case AV_SAMPLE_FMT_S16:
115  ret = twolame_encode_buffer_interleaved(s->glopts,
116  frame->data[0],
117  frame->nb_samples,
118  avpkt->data, avpkt->size);
119  break;
120  case AV_SAMPLE_FMT_S16P:
121  ret = twolame_encode_buffer(s->glopts,
122  frame->data[0], frame->data[1],
123  frame->nb_samples,
124  avpkt->data, avpkt->size);
125  break;
126  default:
127  return AVERROR_BUG;
128  }
129  } else {
130  ret = twolame_encode_flush(s->glopts, avpkt->data, avpkt->size);
131  }
132 
133  if (ret > 0) {
134  avpkt->duration = ff_samples_to_time_base(avctx, avctx->frame_size);
135  if (frame) {
136  if (frame->pts != AV_NOPTS_VALUE)
137  avpkt->pts = frame->pts;
138  } else {
139  avpkt->pts = s->next_pts;
140  }
141  if (avpkt->pts != AV_NOPTS_VALUE)
142  s->next_pts = avpkt->pts + avpkt->duration;
143 
144  avpkt->size = ret;
145  *got_packet_ptr = 1;
146  return 0;
147  }
148 
149  return ret;
150 }
151 
152 #define OFFSET(x) offsetof(TWOLAMEContext, x)
153 #define AE AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
154 static const AVOption options[] = {
155  { "mode", "Mpeg Mode", OFFSET(mode), AV_OPT_TYPE_INT, { .i64 = TWOLAME_AUTO_MODE }, TWOLAME_AUTO_MODE, TWOLAME_MONO, AE, "mode"},
156  { "auto", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_AUTO_MODE }, 0, 0, AE, "mode" },
157  { "stereo", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_STEREO }, 0, 0, AE, "mode" },
158  { "joint_stereo", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_JOINT_STEREO }, 0, 0, AE, "mode" },
159  { "dual_channel", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_DUAL_CHANNEL }, 0, 0, AE, "mode" },
160  { "mono", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_MONO }, 0, 0, AE, "mode" },
161  { "psymodel", "Psychoacoustic Model", OFFSET(psymodel), AV_OPT_TYPE_INT, { .i64 = 3 }, -1, 4, AE},
162  { "energy_levels","enable energy levels", OFFSET(energy), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE},
163  { "error_protection","enable CRC error protection", OFFSET(error_protection), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE},
164  { "copyright", "set MPEG Audio Copyright flag", OFFSET(copyright), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE},
165  { "original", "set MPEG Audio Original flag", OFFSET(original), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE},
166  { NULL },
167 };
168 
169 static const AVClass libtwolame_class = {
170  .class_name = "libtwolame encoder",
171  .item_name = av_default_item_name,
172  .option = options,
173  .version = LIBAVUTIL_VERSION_INT,
174 };
175 
177  .name = "libtwolame",
178  .type = AVMEDIA_TYPE_AUDIO,
179  .id = AV_CODEC_ID_MP2,
180  .priv_data_size = sizeof(TWOLAMEContext),
182  .encode2 = twolame_encode_frame,
184  .capabilities = CODEC_CAP_DELAY,
185  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
190  .channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_MONO,
192  0 },
193  .supported_samplerates = (const int[]){ 16000, 22050, 24000, 32000, 44100, 48000, 0 },
194  .long_name = NULL_IF_CONFIG_SMALL("libtwolame MP2 (MPEG audio layer 2)"),
195  .priv_class = &libtwolame_class,
196 };