Fix wmv1 encoding if all other msmpeg4-related encoders were disabled.
[ffmpeg.git] / libavcodec / ac3enc_template.c
1 /*
2  * AC-3 encoder float/fixed template
3  * Copyright (c) 2000 Fabrice Bellard
4  * Copyright (c) 2006-2011 Justin Ruggles <justin.ruggles@gmail.com>
5  * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23
24 /**
25  * @file
26  * AC-3 encoder float/fixed template
27  */
28
29 #include <stdint.h>
30
31 #include "libavutil/attributes.h"
32 #include "libavutil/internal.h"
33
34 #include "audiodsp.h"
35 #include "internal.h"
36 #include "ac3enc.h"
37 #include "eac3enc.h"
38
39 /* prototypes for static functions in ac3enc_fixed.c and ac3enc_float.c */
40
41 static void scale_coefficients(AC3EncodeContext *s);
42
43 static int normalize_samples(AC3EncodeContext *s);
44
45 static void clip_coefficients(AudioDSPContext *adsp, CoefType *coef,
46                               unsigned int len);
47
48 static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl);
49
50 static void sum_square_butterfly(AC3EncodeContext *s, CoefSumType sum[4],
51                                  const CoefType *coef0, const CoefType *coef1,
52                                  int len);
53
54 int AC3_NAME(allocate_sample_buffers)(AC3EncodeContext *s)
55 {
56     int ch;
57
58     FF_ALLOC_OR_GOTO(s->avctx, s->windowed_samples, AC3_WINDOW_SIZE *
59                      sizeof(*s->windowed_samples), alloc_fail);
60     FF_ALLOC_OR_GOTO(s->avctx, s->planar_samples, s->channels * sizeof(*s->planar_samples),
61                      alloc_fail);
62     for (ch = 0; ch < s->channels; ch++) {
63         FF_ALLOCZ_OR_GOTO(s->avctx, s->planar_samples[ch],
64                           (AC3_FRAME_SIZE+AC3_BLOCK_SIZE) * sizeof(**s->planar_samples),
65                           alloc_fail);
66     }
67
68     return 0;
69 alloc_fail:
70     return AVERROR(ENOMEM);
71 }
72
73
74 /*
75  * Copy input samples.
76  * Channels are reordered from FFmpeg's default order to AC-3 order.
77  */
78 static void copy_input_samples(AC3EncodeContext *s, SampleType **samples)
79 {
80     int ch;
81
82     /* copy and remap input samples */
83     for (ch = 0; ch < s->channels; ch++) {
84         /* copy last 256 samples of previous frame to the start of the current frame */
85         memcpy(&s->planar_samples[ch][0], &s->planar_samples[ch][AC3_BLOCK_SIZE * s->num_blocks],
86                AC3_BLOCK_SIZE * sizeof(s->planar_samples[0][0]));
87
88         /* copy new samples for current frame */
89         memcpy(&s->planar_samples[ch][AC3_BLOCK_SIZE],
90                samples[s->channel_map[ch]],
91                AC3_BLOCK_SIZE * s->num_blocks * sizeof(s->planar_samples[0][0]));
92     }
93 }
94
95
96 /*
97  * Apply the MDCT to input samples to generate frequency coefficients.
98  * This applies the KBD window and normalizes the input to reduce precision
99  * loss due to fixed-point calculations.
100  */
101 static void apply_mdct(AC3EncodeContext *s)
102 {
103     int blk, ch;
104
105     for (ch = 0; ch < s->channels; ch++) {
106         for (blk = 0; blk < s->num_blocks; blk++) {
107             AC3Block *block = &s->blocks[blk];
108             const SampleType *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
109
110 #if CONFIG_AC3ENC_FLOAT
111             s->fdsp.vector_fmul(s->windowed_samples, input_samples,
112                                 s->mdct_window, AC3_WINDOW_SIZE);
113 #else
114             s->ac3dsp.apply_window_int16(s->windowed_samples, input_samples,
115                                          s->mdct_window, AC3_WINDOW_SIZE);
116 #endif
117
118             if (s->fixed_point)
119                 block->coeff_shift[ch+1] = normalize_samples(s);
120
121             s->mdct.mdct_calcw(&s->mdct, block->mdct_coef[ch+1],
122                                s->windowed_samples);
123         }
124     }
125 }
126
127
128 /*
129  * Calculate coupling channel and coupling coordinates.
130  */
131 static void apply_channel_coupling(AC3EncodeContext *s)
132 {
133     LOCAL_ALIGNED_16(CoefType, cpl_coords,      [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
134 #if CONFIG_AC3ENC_FLOAT
135     LOCAL_ALIGNED_16(int32_t, fixed_cpl_coords, [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
136 #else
137     int32_t (*fixed_cpl_coords)[AC3_MAX_CHANNELS][16] = cpl_coords;
138 #endif
139     int av_uninit(blk), ch, bnd, i, j;
140     CoefSumType energy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][16] = {{{0}}};
141     int cpl_start, num_cpl_coefs;
142
143     memset(cpl_coords,       0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
144 #if CONFIG_AC3ENC_FLOAT
145     memset(fixed_cpl_coords, 0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
146 #endif
147
148     /* align start to 16-byte boundary. align length to multiple of 32.
149         note: coupling start bin % 4 will always be 1 */
150     cpl_start     = s->start_freq[CPL_CH] - 1;
151     num_cpl_coefs = FFALIGN(s->num_cpl_subbands * 12 + 1, 32);
152     cpl_start     = FFMIN(256, cpl_start + num_cpl_coefs) - num_cpl_coefs;
153
154     /* calculate coupling channel from fbw channels */
155     for (blk = 0; blk < s->num_blocks; blk++) {
156         AC3Block *block = &s->blocks[blk];
157         CoefType *cpl_coef = &block->mdct_coef[CPL_CH][cpl_start];
158         if (!block->cpl_in_use)
159             continue;
160         memset(cpl_coef, 0, num_cpl_coefs * sizeof(*cpl_coef));
161         for (ch = 1; ch <= s->fbw_channels; ch++) {
162             CoefType *ch_coef = &block->mdct_coef[ch][cpl_start];
163             if (!block->channel_in_cpl[ch])
164                 continue;
165             for (i = 0; i < num_cpl_coefs; i++)
166                 cpl_coef[i] += ch_coef[i];
167         }
168
169         /* coefficients must be clipped in order to be encoded */
170         clip_coefficients(&s->adsp, cpl_coef, num_cpl_coefs);
171     }
172
173     /* calculate energy in each band in coupling channel and each fbw channel */
174     /* TODO: possibly use SIMD to speed up energy calculation */
175     bnd = 0;
176     i = s->start_freq[CPL_CH];
177     while (i < s->cpl_end_freq) {
178         int band_size = s->cpl_band_sizes[bnd];
179         for (ch = CPL_CH; ch <= s->fbw_channels; ch++) {
180             for (blk = 0; blk < s->num_blocks; blk++) {
181                 AC3Block *block = &s->blocks[blk];
182                 if (!block->cpl_in_use || (ch > CPL_CH && !block->channel_in_cpl[ch]))
183                     continue;
184                 for (j = 0; j < band_size; j++) {
185                     CoefType v = block->mdct_coef[ch][i+j];
186                     MAC_COEF(energy[blk][ch][bnd], v, v);
187                 }
188             }
189         }
190         i += band_size;
191         bnd++;
192     }
193
194     /* calculate coupling coordinates for all blocks for all channels */
195     for (blk = 0; blk < s->num_blocks; blk++) {
196         AC3Block *block  = &s->blocks[blk];
197         if (!block->cpl_in_use)
198             continue;
199         for (ch = 1; ch <= s->fbw_channels; ch++) {
200             if (!block->channel_in_cpl[ch])
201                 continue;
202             for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
203                 cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy[blk][ch][bnd],
204                                                           energy[blk][CPL_CH][bnd]);
205             }
206         }
207     }
208
209     /* determine which blocks to send new coupling coordinates for */
210     for (blk = 0; blk < s->num_blocks; blk++) {
211         AC3Block *block  = &s->blocks[blk];
212         AC3Block *block0 = blk ? &s->blocks[blk-1] : NULL;
213
214         memset(block->new_cpl_coords, 0, sizeof(block->new_cpl_coords));
215
216         if (block->cpl_in_use) {
217             /* send new coordinates if this is the first block, if previous
218              * block did not use coupling but this block does, the channels
219              * using coupling has changed from the previous block, or the
220              * coordinate difference from the last block for any channel is
221              * greater than a threshold value. */
222             if (blk == 0 || !block0->cpl_in_use) {
223                 for (ch = 1; ch <= s->fbw_channels; ch++)
224                     block->new_cpl_coords[ch] = 1;
225             } else {
226                 for (ch = 1; ch <= s->fbw_channels; ch++) {
227                     if (!block->channel_in_cpl[ch])
228                         continue;
229                     if (!block0->channel_in_cpl[ch]) {
230                         block->new_cpl_coords[ch] = 1;
231                     } else {
232                         CoefSumType coord_diff = 0;
233                         for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
234                             coord_diff += FFABS(cpl_coords[blk-1][ch][bnd] -
235                                                 cpl_coords[blk  ][ch][bnd]);
236                         }
237                         coord_diff /= s->num_cpl_bands;
238                         if (coord_diff > NEW_CPL_COORD_THRESHOLD)
239                             block->new_cpl_coords[ch] = 1;
240                     }
241                 }
242             }
243         }
244     }
245
246     /* calculate final coupling coordinates, taking into account reusing of
247        coordinates in successive blocks */
248     for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
249         blk = 0;
250         while (blk < s->num_blocks) {
251             int av_uninit(blk1);
252             AC3Block *block  = &s->blocks[blk];
253
254             if (!block->cpl_in_use) {
255                 blk++;
256                 continue;
257             }
258
259             for (ch = 1; ch <= s->fbw_channels; ch++) {
260                 CoefSumType energy_ch, energy_cpl;
261                 if (!block->channel_in_cpl[ch])
262                     continue;
263                 energy_cpl = energy[blk][CPL_CH][bnd];
264                 energy_ch = energy[blk][ch][bnd];
265                 blk1 = blk+1;
266                 while (!s->blocks[blk1].new_cpl_coords[ch] && blk1 < s->num_blocks) {
267                     if (s->blocks[blk1].cpl_in_use) {
268                         energy_cpl += energy[blk1][CPL_CH][bnd];
269                         energy_ch += energy[blk1][ch][bnd];
270                     }
271                     blk1++;
272                 }
273                 cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy_ch, energy_cpl);
274             }
275             blk = blk1;
276         }
277     }
278
279     /* calculate exponents/mantissas for coupling coordinates */
280     for (blk = 0; blk < s->num_blocks; blk++) {
281         AC3Block *block = &s->blocks[blk];
282         if (!block->cpl_in_use)
283             continue;
284
285 #if CONFIG_AC3ENC_FLOAT
286         s->ac3dsp.float_to_fixed24(fixed_cpl_coords[blk][1],
287                                    cpl_coords[blk][1],
288                                    s->fbw_channels * 16);
289 #endif
290         s->ac3dsp.extract_exponents(block->cpl_coord_exp[1],
291                                     fixed_cpl_coords[blk][1],
292                                     s->fbw_channels * 16);
293
294         for (ch = 1; ch <= s->fbw_channels; ch++) {
295             int bnd, min_exp, max_exp, master_exp;
296
297             if (!block->new_cpl_coords[ch])
298                 continue;
299
300             /* determine master exponent */
301             min_exp = max_exp = block->cpl_coord_exp[ch][0];
302             for (bnd = 1; bnd < s->num_cpl_bands; bnd++) {
303                 int exp = block->cpl_coord_exp[ch][bnd];
304                 min_exp = FFMIN(exp, min_exp);
305                 max_exp = FFMAX(exp, max_exp);
306             }
307             master_exp = ((max_exp - 15) + 2) / 3;
308             master_exp = FFMAX(master_exp, 0);
309             while (min_exp < master_exp * 3)
310                 master_exp--;
311             for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
312                 block->cpl_coord_exp[ch][bnd] = av_clip(block->cpl_coord_exp[ch][bnd] -
313                                                         master_exp * 3, 0, 15);
314             }
315             block->cpl_master_exp[ch] = master_exp;
316
317             /* quantize mantissas */
318             for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
319                 int cpl_exp  = block->cpl_coord_exp[ch][bnd];
320                 int cpl_mant = (fixed_cpl_coords[blk][ch][bnd] << (5 + cpl_exp + master_exp * 3)) >> 24;
321                 if (cpl_exp == 15)
322                     cpl_mant >>= 1;
323                 else
324                     cpl_mant -= 16;
325
326                 block->cpl_coord_mant[ch][bnd] = cpl_mant;
327             }
328         }
329     }
330
331     if (CONFIG_EAC3_ENCODER && s->eac3)
332         ff_eac3_set_cpl_states(s);
333 }
334
335
336 /*
337  * Determine rematrixing flags for each block and band.
338  */
339 static void compute_rematrixing_strategy(AC3EncodeContext *s)
340 {
341     int nb_coefs;
342     int blk, bnd;
343     AC3Block *block, *block0 = NULL;
344
345     if (s->channel_mode != AC3_CHMODE_STEREO)
346         return;
347
348     for (blk = 0; blk < s->num_blocks; blk++) {
349         block = &s->blocks[blk];
350         block->new_rematrixing_strategy = !blk;
351
352         block->num_rematrixing_bands = 4;
353         if (block->cpl_in_use) {
354             block->num_rematrixing_bands -= (s->start_freq[CPL_CH] <= 61);
355             block->num_rematrixing_bands -= (s->start_freq[CPL_CH] == 37);
356             if (blk && block->num_rematrixing_bands != block0->num_rematrixing_bands)
357                 block->new_rematrixing_strategy = 1;
358         }
359         nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
360
361         if (!s->rematrixing_enabled) {
362             block0 = block;
363             continue;
364         }
365
366         for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
367             /* calculate sum of squared coeffs for one band in one block */
368             int start = ff_ac3_rematrix_band_tab[bnd];
369             int end   = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
370             CoefSumType sum[4];
371             sum_square_butterfly(s, sum, block->mdct_coef[1] + start,
372                                  block->mdct_coef[2] + start, end - start);
373
374             /* compare sums to determine if rematrixing will be used for this band */
375             if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1]))
376                 block->rematrixing_flags[bnd] = 1;
377             else
378                 block->rematrixing_flags[bnd] = 0;
379
380             /* determine if new rematrixing flags will be sent */
381             if (blk &&
382                 block->rematrixing_flags[bnd] != block0->rematrixing_flags[bnd]) {
383                 block->new_rematrixing_strategy = 1;
384             }
385         }
386         block0 = block;
387     }
388 }
389
390
391 int AC3_NAME(encode_frame)(AVCodecContext *avctx, AVPacket *avpkt,
392                            const AVFrame *frame, int *got_packet_ptr)
393 {
394     AC3EncodeContext *s = avctx->priv_data;
395     int ret;
396
397     if (s->options.allow_per_frame_metadata) {
398         ret = ff_ac3_validate_metadata(s);
399         if (ret)
400             return ret;
401     }
402
403     if (s->bit_alloc.sr_code == 1 || s->eac3)
404         ff_ac3_adjust_frame_size(s);
405
406     copy_input_samples(s, (SampleType **)frame->extended_data);
407
408     apply_mdct(s);
409
410     if (s->fixed_point)
411         scale_coefficients(s);
412
413     clip_coefficients(&s->adsp, s->blocks[0].mdct_coef[1],
414                       AC3_MAX_COEFS * s->num_blocks * s->channels);
415
416     s->cpl_on = s->cpl_enabled;
417     ff_ac3_compute_coupling_strategy(s);
418
419     if (s->cpl_on)
420         apply_channel_coupling(s);
421
422     compute_rematrixing_strategy(s);
423
424     if (!s->fixed_point)
425         scale_coefficients(s);
426
427     ff_ac3_apply_rematrixing(s);
428
429     ff_ac3_process_exponents(s);
430
431     ret = ff_ac3_compute_bit_allocation(s);
432     if (ret) {
433         av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
434         return ret;
435     }
436
437     ff_ac3_group_exponents(s);
438
439     ff_ac3_quantize_mantissas(s);
440
441     if ((ret = ff_alloc_packet2(avctx, avpkt, s->frame_size)) < 0)
442         return ret;
443     ff_ac3_output_frame(s, avpkt->data);
444
445     if (frame->pts != AV_NOPTS_VALUE)
446         avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->delay);
447
448     *got_packet_ptr = 1;
449     return 0;
450 }