1 /*****************************************************************************
2 * twolame.c: libtwolame encoder (MPEG-1/2 layer II) module
3 * (using libtwolame from http://www.twolame.org/)
4 *****************************************************************************
5 * Copyright (C) 2004-2005 VLC authors and VideoLAN
6 * $Id: 6fdad1164c69ebe4f3572871ab423c0298949f6b $
7 *
8 * Authors: Christophe Massiot <massiot@via.ecp.fr>
9 * Gildas Bazin
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU Lesser General Public License as published by
13 * the Free Software Foundation; either version 2.1 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public License
22 * along with this program; if not, write to the Free Software Foundation,
23 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
24 *****************************************************************************/
25
26 /*****************************************************************************
27 * Preamble
28 *****************************************************************************/
29 #ifdef HAVE_CONFIG_H
30 # include "config.h"
31 #endif
32
33 #include <vlc_common.h>
34 #include <vlc_plugin.h>
35 #include <vlc_codec.h>
36
37 #include <twolame.h>
38
39 #define MPEG_FRAME_SIZE 1152
40 #define MAX_CODED_FRAME_SIZE 1792
41
42 /****************************************************************************
43 * Local prototypes
44 ****************************************************************************/
45 static int OpenEncoder ( vlc_object_t * );
46 static void CloseEncoder ( vlc_object_t * );
47 static block_t *Encode ( encoder_t *, block_t * );
48
49 /*****************************************************************************
50 * Module descriptor
51 *****************************************************************************/
52 #define ENC_CFG_PREFIX "sout-twolame-"
53
54 #define ENC_QUALITY_TEXT N_("Encoding quality")
55 #define ENC_QUALITY_LONGTEXT N_( \
56 "Force a specific encoding quality between 0.0 (high) and 50.0 (low), " \
57 "instead of specifying a particular bitrate. " \
58 "This will produce a VBR stream." )
59 #define ENC_MODE_TEXT N_("Stereo mode")
60 #define ENC_MODE_LONGTEXT N_( "Handling mode for stereo streams" )
61 #define ENC_VBR_TEXT N_("VBR mode")
62 #define ENC_VBR_LONGTEXT N_( \
63 "Use Variable BitRate. Default is to use Constant BitRate (CBR)." )
64 #define ENC_PSY_TEXT N_("Psycho-acoustic model")
65 #define ENC_PSY_LONGTEXT N_( \
66 "Integer from -1 (no model) to 4." )
67
68 static const int pi_stereo_values[] = { 0, 1, 2 };
69 static const char *const ppsz_stereo_descriptions[] =
70 { N_("Stereo"), N_("Dual mono"), N_("Joint stereo") };
71
72
73 vlc_module_begin ()
74 set_shortname( "Twolame")
75 set_description( N_("Libtwolame audio encoder") )
76 set_capability( "encoder", 120 )
77 set_callbacks( OpenEncoder, CloseEncoder )
78 set_category( CAT_INPUT )
79 set_subcategory( SUBCAT_INPUT_ACODEC )
80
81 add_float( ENC_CFG_PREFIX "quality", 0.0, ENC_QUALITY_TEXT,
82 ENC_QUALITY_LONGTEXT, false )
83 add_integer( ENC_CFG_PREFIX "mode", 0, ENC_MODE_TEXT,
84 ENC_MODE_LONGTEXT, false )
85 change_integer_list( pi_stereo_values, ppsz_stereo_descriptions );
86 add_bool( ENC_CFG_PREFIX "vbr", false, ENC_VBR_TEXT,
87 ENC_VBR_LONGTEXT, false )
88 add_integer( ENC_CFG_PREFIX "psy", 3, ENC_PSY_TEXT,
89 ENC_PSY_LONGTEXT, false )
90 vlc_module_end ()
91
92 static const char *const ppsz_enc_options[] = {
93 "quality", "mode", "vbr", "psy", NULL
94 };
95
96 /*****************************************************************************
97 * encoder_sys_t : twolame encoder descriptor
98 *****************************************************************************/
99 struct encoder_sys_t
100 {
101 /*
102 * Input properties
103 */
104 int16_t p_buffer[MPEG_FRAME_SIZE * 2];
105 int i_nb_samples;
106 mtime_t i_pts;
107
108 /*
109 * libtwolame properties
110 */
111 twolame_options *p_twolame;
112 unsigned char p_out_buffer[MAX_CODED_FRAME_SIZE];
113 };
114
115 /*****************************************************************************
116 * OpenEncoder: probe the encoder and return score
117 *****************************************************************************/
118 static const uint16_t mpa_bitrate_tab[2][15] =
119 {
120 {0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384},
121 {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160}
122 };
123
124 static const uint16_t mpa_freq_tab[6] =
125 { 44100, 48000, 32000, 22050, 24000, 16000 };
126
OpenEncoder(vlc_object_t * p_this)127 static int OpenEncoder( vlc_object_t *p_this )
128 {
129 encoder_t *p_enc = (encoder_t *)p_this;
130 encoder_sys_t *p_sys;
131 int i_frequency;
132
133 if( p_enc->fmt_out.i_codec != VLC_CODEC_MP2 &&
134 p_enc->fmt_out.i_codec != VLC_CODEC_MPGA &&
135 p_enc->fmt_out.i_codec != VLC_FOURCC( 'm', 'p', '2', 'a' ) &&
136 !p_enc->obj.force )
137 {
138 return VLC_EGENERIC;
139 }
140
141 if( p_enc->fmt_in.audio.i_channels > 2 )
142 {
143 msg_Err( p_enc, "doesn't support > 2 channels" );
144 return VLC_EGENERIC;
145 }
146
147 for ( i_frequency = 0; i_frequency < 6; i_frequency++ )
148 {
149 if ( p_enc->fmt_out.audio.i_rate == mpa_freq_tab[i_frequency] )
150 break;
151 }
152 if ( i_frequency == 6 )
153 {
154 msg_Err( p_enc, "MPEG audio doesn't support frequency=%d",
155 p_enc->fmt_out.audio.i_rate );
156 return VLC_EGENERIC;
157 }
158
159 /* Allocate the memory needed to store the decoder's structure */
160 if( ( p_sys = (encoder_sys_t *)malloc(sizeof(encoder_sys_t)) ) == NULL )
161 return VLC_ENOMEM;
162 p_enc->p_sys = p_sys;
163
164 p_enc->fmt_in.i_codec = VLC_CODEC_S16N;
165
166 p_enc->fmt_out.i_cat = AUDIO_ES;
167 p_enc->fmt_out.i_codec = VLC_CODEC_MPGA;
168
169 config_ChainParse( p_enc, ENC_CFG_PREFIX, ppsz_enc_options, p_enc->p_cfg );
170
171 p_sys->p_twolame = twolame_init();
172
173 /* Set options */
174 twolame_set_in_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
175 twolame_set_out_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
176
177 if( var_GetBool( p_enc, ENC_CFG_PREFIX "vbr" ) )
178 {
179 float f_quality = var_GetFloat( p_enc, ENC_CFG_PREFIX "quality" );
180 if ( f_quality > 50.f ) f_quality = 50.f;
181 if ( f_quality < 0.f ) f_quality = 0.f;
182 twolame_set_VBR( p_sys->p_twolame, 1 );
183 twolame_set_VBR_q( p_sys->p_twolame, f_quality );
184 }
185 else
186 {
187 int i;
188 for ( i = 1; i < 14; i++ )
189 {
190 if ( p_enc->fmt_out.i_bitrate / 1000
191 <= mpa_bitrate_tab[i_frequency / 3][i] )
192 break;
193 }
194 if ( p_enc->fmt_out.i_bitrate / 1000
195 != mpa_bitrate_tab[i_frequency / 3][i] )
196 {
197 msg_Warn( p_enc, "MPEG audio doesn't support bitrate=%d, using %d",
198 p_enc->fmt_out.i_bitrate,
199 mpa_bitrate_tab[i_frequency / 3][i] * 1000 );
200 p_enc->fmt_out.i_bitrate = mpa_bitrate_tab[i_frequency / 3][i]
201 * 1000;
202 }
203
204 twolame_set_bitrate( p_sys->p_twolame,
205 p_enc->fmt_out.i_bitrate / 1000 );
206 }
207
208 if ( p_enc->fmt_in.audio.i_channels == 1 )
209 {
210 twolame_set_num_channels( p_sys->p_twolame, 1 );
211 twolame_set_mode( p_sys->p_twolame, TWOLAME_MONO );
212 }
213 else
214 {
215 twolame_set_num_channels( p_sys->p_twolame, 2 );
216 switch( var_GetInteger( p_enc, ENC_CFG_PREFIX "mode" ) )
217 {
218 case 1:
219 twolame_set_mode( p_sys->p_twolame, TWOLAME_DUAL_CHANNEL );
220 break;
221 case 2:
222 twolame_set_mode( p_sys->p_twolame, TWOLAME_JOINT_STEREO );
223 break;
224 case 0:
225 default:
226 twolame_set_mode( p_sys->p_twolame, TWOLAME_STEREO );
227 break;
228 }
229 }
230
231 twolame_set_psymodel( p_sys->p_twolame,
232 var_GetInteger( p_enc, ENC_CFG_PREFIX "psy" ) );
233
234 if ( twolame_init_params( p_sys->p_twolame ) )
235 {
236 msg_Err( p_enc, "twolame initialization failed" );
237 return -VLC_EGENERIC;
238 }
239
240 p_enc->pf_encode_audio = Encode;
241
242 p_sys->i_nb_samples = 0;
243
244 return VLC_SUCCESS;
245 }
246
247 /****************************************************************************
248 * Encode: the whole thing
249 ****************************************************************************
250 * This function spits out MPEG packets.
251 ****************************************************************************/
Bufferize(encoder_t * p_enc,int16_t * p_in,int i_nb_samples)252 static void Bufferize( encoder_t *p_enc, int16_t *p_in, int i_nb_samples )
253 {
254 encoder_sys_t *p_sys = p_enc->p_sys;
255 const unsigned i_offset = p_sys->i_nb_samples * p_enc->fmt_in.audio.i_channels;
256 const unsigned i_len = ARRAY_SIZE(p_sys->p_buffer);
257
258 if( i_offset >= i_len )
259 {
260 msg_Err( p_enc, "buffer full" );
261 return;
262 }
263
264 unsigned i_copy = i_nb_samples * p_enc->fmt_in.audio.i_channels;
265 if( i_copy + i_offset > i_len)
266 {
267 msg_Err( p_enc, "dropping samples" );
268 i_copy = i_len - i_offset;
269 }
270
271 memcpy( p_sys->p_buffer + i_offset, p_in, i_copy * sizeof(int16_t) );
272 }
273
Encode(encoder_t * p_enc,block_t * p_aout_buf)274 static block_t *Encode( encoder_t *p_enc, block_t *p_aout_buf )
275 {
276 encoder_sys_t *p_sys = p_enc->p_sys;
277 block_t *p_chain = NULL;
278
279 if( unlikely( !p_aout_buf ) ) {
280 int i_used = 0;
281 block_t *p_block;
282
283 i_used = twolame_encode_flush( p_sys->p_twolame,
284 p_sys->p_out_buffer, MAX_CODED_FRAME_SIZE );
285 if( i_used <= 0 )
286 return NULL;
287
288 p_block = block_Alloc( i_used );
289 if( !p_block )
290 return NULL;
291 memcpy( p_block->p_buffer, p_sys->p_out_buffer, i_used );
292 p_block->i_length = CLOCK_FREQ *
293 (mtime_t)MPEG_FRAME_SIZE / (mtime_t)p_enc->fmt_out.audio.i_rate;
294 p_block->i_dts = p_block->i_pts = p_sys->i_pts;
295 p_sys->i_pts += p_block->i_length;
296
297 return p_block;
298 }
299
300 int16_t *p_buffer = (int16_t *)p_aout_buf->p_buffer;
301 int i_nb_samples = p_aout_buf->i_nb_samples;
302
303 p_sys->i_pts = p_aout_buf->i_pts -
304 (mtime_t)1000000 * (mtime_t)p_sys->i_nb_samples /
305 (mtime_t)p_enc->fmt_out.audio.i_rate;
306
307 while ( p_sys->i_nb_samples + i_nb_samples >= MPEG_FRAME_SIZE )
308 {
309 int i_used;
310 block_t *p_block;
311
312 Bufferize( p_enc, p_buffer, MPEG_FRAME_SIZE - p_sys->i_nb_samples );
313 i_nb_samples -= MPEG_FRAME_SIZE - p_sys->i_nb_samples;
314 p_buffer += (MPEG_FRAME_SIZE - p_sys->i_nb_samples) * 2;
315
316 i_used = twolame_encode_buffer_interleaved( p_sys->p_twolame,
317 p_sys->p_buffer, MPEG_FRAME_SIZE,
318 p_sys->p_out_buffer, MAX_CODED_FRAME_SIZE );
319 /* On error, buffer samples and return what was already encoded */
320 if( i_used < 0 )
321 {
322 msg_Err( p_enc, "encoder error: %d", i_used );
323 break;
324 }
325
326 p_sys->i_nb_samples = 0;
327 p_block = block_Alloc( i_used );
328 if( !p_block )
329 {
330 if( p_chain )
331 block_ChainRelease( p_chain );
332 return NULL;
333 }
334 memcpy( p_block->p_buffer, p_sys->p_out_buffer, i_used );
335 p_block->i_length = CLOCK_FREQ *
336 (mtime_t)MPEG_FRAME_SIZE / (mtime_t)p_enc->fmt_out.audio.i_rate;
337 p_block->i_dts = p_block->i_pts = p_sys->i_pts;
338 p_sys->i_pts += p_block->i_length;
339 block_ChainAppend( &p_chain, p_block );
340 }
341
342 if ( i_nb_samples )
343 {
344 Bufferize( p_enc, p_buffer, i_nb_samples );
345 p_sys->i_nb_samples += i_nb_samples;
346 }
347
348 return p_chain;
349 }
350
351 /*****************************************************************************
352 * CloseEncoder: twolame encoder destruction
353 *****************************************************************************/
CloseEncoder(vlc_object_t * p_this)354 static void CloseEncoder( vlc_object_t *p_this )
355 {
356 encoder_t *p_enc = (encoder_t *)p_this;
357 encoder_sys_t *p_sys = p_enc->p_sys;
358
359 twolame_close( &p_sys->p_twolame );
360
361 free( p_sys );
362 }
363