1 /*
2 * H.26L/H.264/AVC/JVT/14496-10/... SEI decoding
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
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 * H.264 / AVC / MPEG-4 part10 SEI decoding.
25 * @author Michael Niedermayer <michaelni@gmx.at>
26 */
27
28 #include <limits.h>
29 #include <stdio.h>
30 #include <string.h>
31 #include "libavutil/error.h"
32 #include "libavutil/log.h"
33 #include "libavutil/macros.h"
34 #include "libavutil/mem.h"
35 #include "atsc_a53.h"
36 #include "get_bits.h"
37 #include "golomb.h"
38 #include "h264_ps.h"
39 #include "h264_sei.h"
40 #include "sei.h"
41
42 #define AVERROR_PS_NOT_FOUND FFERRTAG(0xF8,'?','P','S')
43
44 static const uint8_t sei_num_clock_ts_table[9] = {
45 1, 1, 1, 2, 2, 3, 3, 2, 3
46 };
47
ff_h264_sei_uninit(H264SEIContext *h)48 void ff_h264_sei_uninit(H264SEIContext *h)
49 {
50 h->recovery_point.recovery_frame_cnt = -1;
51
52 h->picture_timing.dpb_output_delay = 0;
53 h->picture_timing.cpb_removal_delay = -1;
54
55 h->picture_timing.present = 0;
56 h->buffering_period.present = 0;
57 h->frame_packing.present = 0;
58 h->film_grain_characteristics.present = 0;
59 h->display_orientation.present = 0;
60 h->afd.present = 0;
61
62 av_buffer_unref(&h->a53_caption.buf_ref);
63 for (int i = 0; i < h->unregistered.nb_buf_ref; i++)
64 av_buffer_unref(&h->unregistered.buf_ref[i]);
65 h->unregistered.nb_buf_ref = 0;
66 av_freep(&h->unregistered.buf_ref);
67 }
68
ff_h264_sei_process_picture_timing(H264SEIPictureTiming *h, const SPS *sps, void *logctx)69 int ff_h264_sei_process_picture_timing(H264SEIPictureTiming *h, const SPS *sps,
70 void *logctx)
71 {
72 GetBitContext gb;
73
74 init_get_bits(&gb, h->payload, h->payload_size_bits);
75
76 if (sps->nal_hrd_parameters_present_flag ||
77 sps->vcl_hrd_parameters_present_flag) {
78 h->cpb_removal_delay = get_bits_long(&gb, sps->cpb_removal_delay_length);
79 h->dpb_output_delay = get_bits_long(&gb, sps->dpb_output_delay_length);
80 }
81 if (sps->pic_struct_present_flag) {
82 unsigned int i, num_clock_ts;
83
84 h->pic_struct = get_bits(&gb, 4);
85 h->ct_type = 0;
86
87 if (h->pic_struct > H264_SEI_PIC_STRUCT_FRAME_TRIPLING)
88 return AVERROR_INVALIDDATA;
89
90 num_clock_ts = sei_num_clock_ts_table[h->pic_struct];
91 h->timecode_cnt = 0;
92 for (i = 0; i < num_clock_ts; i++) {
93 if (get_bits(&gb, 1)) { /* clock_timestamp_flag */
94 H264SEITimeCode *tc = &h->timecode[h->timecode_cnt++];
95 unsigned int full_timestamp_flag;
96 unsigned int counting_type, cnt_dropped_flag;
97 h->ct_type |= 1 << get_bits(&gb, 2);
98 skip_bits(&gb, 1); /* nuit_field_based_flag */
99 counting_type = get_bits(&gb, 5); /* counting_type */
100 full_timestamp_flag = get_bits(&gb, 1);
101 skip_bits(&gb, 1); /* discontinuity_flag */
102 cnt_dropped_flag = get_bits(&gb, 1); /* cnt_dropped_flag */
103 if (cnt_dropped_flag && counting_type > 1 && counting_type < 7)
104 tc->dropframe = 1;
105 tc->frame = get_bits(&gb, 8); /* n_frames */
106 if (full_timestamp_flag) {
107 tc->full = 1;
108 tc->seconds = get_bits(&gb, 6); /* seconds_value 0..59 */
109 tc->minutes = get_bits(&gb, 6); /* minutes_value 0..59 */
110 tc->hours = get_bits(&gb, 5); /* hours_value 0..23 */
111 } else {
112 tc->seconds = tc->minutes = tc->hours = tc->full = 0;
113 if (get_bits(&gb, 1)) { /* seconds_flag */
114 tc->seconds = get_bits(&gb, 6);
115 if (get_bits(&gb, 1)) { /* minutes_flag */
116 tc->minutes = get_bits(&gb, 6);
117 if (get_bits(&gb, 1)) /* hours_flag */
118 tc->hours = get_bits(&gb, 5);
119 }
120 }
121 }
122
123 if (sps->time_offset_length > 0)
124 skip_bits(&gb,
125 sps->time_offset_length); /* time_offset */
126 }
127 }
128
129 av_log(logctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n",
130 h->ct_type, h->pic_struct);
131 }
132
133 return 0;
134 }
135
decode_picture_timing(H264SEIPictureTiming *h, GetBitContext *gb, void *logctx)136 static int decode_picture_timing(H264SEIPictureTiming *h, GetBitContext *gb,
137 void *logctx)
138 {
139 int index = get_bits_count(gb);
140 int size_bits = get_bits_left(gb);
141 int size = (size_bits + 7) / 8;
142
143 if (index & 7) {
144 av_log(logctx, AV_LOG_ERROR, "Unaligned SEI payload\n");
145 return AVERROR_INVALIDDATA;
146 }
147 if (size > sizeof(h->payload)) {
148 av_log(logctx, AV_LOG_ERROR, "Picture timing SEI payload too large\n");
149 return AVERROR_INVALIDDATA;
150 }
151 memcpy(h->payload, gb->buffer + index / 8, size);
152
153 h->payload_size_bits = size_bits;
154
155 h->present = 1;
156 return 0;
157 }
158
decode_registered_user_data_afd(H264SEIAFD *h, GetBitContext *gb, int size)159 static int decode_registered_user_data_afd(H264SEIAFD *h, GetBitContext *gb, int size)
160 {
161 int flag;
162
163 if (size-- < 1)
164 return AVERROR_INVALIDDATA;
165 skip_bits(gb, 1); // 0
166 flag = get_bits(gb, 1); // active_format_flag
167 skip_bits(gb, 6); // reserved
168
169 if (flag) {
170 if (size-- < 1)
171 return AVERROR_INVALIDDATA;
172 skip_bits(gb, 4); // reserved
173 h->active_format_description = get_bits(gb, 4);
174 h->present = 1;
175 }
176
177 return 0;
178 }
179
decode_registered_user_data_closed_caption(H264SEIA53Caption *h, GetBitContext *gb, void *logctx, int size)180 static int decode_registered_user_data_closed_caption(H264SEIA53Caption *h,
181 GetBitContext *gb, void *logctx,
182 int size)
183 {
184 if (size < 3)
185 return AVERROR(EINVAL);
186
187 return ff_parse_a53_cc(&h->buf_ref, gb->buffer + get_bits_count(gb) / 8, size);
188 }
189
decode_registered_user_data(H264SEIContext *h, GetBitContext *gb, void *logctx, int size)190 static int decode_registered_user_data(H264SEIContext *h, GetBitContext *gb,
191 void *logctx, int size)
192 {
193 int country_code, provider_code;
194
195 if (size < 3)
196 return AVERROR_INVALIDDATA;
197 size -= 3;
198
199 country_code = get_bits(gb, 8); // itu_t_t35_country_code
200 if (country_code == 0xFF) {
201 if (size < 1)
202 return AVERROR_INVALIDDATA;
203
204 skip_bits(gb, 8); // itu_t_t35_country_code_extension_byte
205 size--;
206 }
207
208 if (country_code != 0xB5) { // usa_country_code
209 av_log(logctx, AV_LOG_VERBOSE,
210 "Unsupported User Data Registered ITU-T T35 SEI message (country_code = %d)\n",
211 country_code);
212 return 0;
213 }
214
215 /* itu_t_t35_payload_byte follows */
216 provider_code = get_bits(gb, 16);
217
218 switch (provider_code) {
219 case 0x31: { // atsc_provider_code
220 uint32_t user_identifier;
221
222 if (size < 4)
223 return AVERROR_INVALIDDATA;
224 size -= 4;
225
226 user_identifier = get_bits_long(gb, 32);
227 switch (user_identifier) {
228 case MKBETAG('D', 'T', 'G', '1'): // afd_data
229 return decode_registered_user_data_afd(&h->afd, gb, size);
230 case MKBETAG('G', 'A', '9', '4'): // closed captions
231 return decode_registered_user_data_closed_caption(&h->a53_caption, gb,
232 logctx, size);
233 default:
234 av_log(logctx, AV_LOG_VERBOSE,
235 "Unsupported User Data Registered ITU-T T35 SEI message (atsc user_identifier = 0x%04x)\n",
236 user_identifier);
237 break;
238 }
239 break;
240 }
241 default:
242 av_log(logctx, AV_LOG_VERBOSE,
243 "Unsupported User Data Registered ITU-T T35 SEI message (provider_code = %d)\n",
244 provider_code);
245 break;
246 }
247
248 return 0;
249 }
250
decode_unregistered_user_data(H264SEIUnregistered *h, GetBitContext *gb, void *logctx, int size)251 static int decode_unregistered_user_data(H264SEIUnregistered *h, GetBitContext *gb,
252 void *logctx, int size)
253 {
254 uint8_t *user_data;
255 int e, build, i;
256 AVBufferRef *buf_ref, **tmp;
257
258 if (size < 16 || size >= INT_MAX - 1)
259 return AVERROR_INVALIDDATA;
260
261 tmp = av_realloc_array(h->buf_ref, h->nb_buf_ref + 1, sizeof(*h->buf_ref));
262 if (!tmp)
263 return AVERROR(ENOMEM);
264 h->buf_ref = tmp;
265
266 buf_ref = av_buffer_alloc(size + 1);
267 if (!buf_ref)
268 return AVERROR(ENOMEM);
269 user_data = buf_ref->data;
270
271 for (i = 0; i < size; i++)
272 user_data[i] = get_bits(gb, 8);
273
274 user_data[i] = 0;
275 buf_ref->size = size;
276 h->buf_ref[h->nb_buf_ref++] = buf_ref;
277
278 e = sscanf(user_data + 16, "x264 - core %d", &build);
279 if (e == 1 && build > 0)
280 h->x264_build = build;
281 if (e == 1 && build == 1 && !strncmp(user_data+16, "x264 - core 0000", 16))
282 h->x264_build = 67;
283
284 return 0;
285 }
286
decode_recovery_point(H264SEIRecoveryPoint *h, GetBitContext *gb, void *logctx)287 static int decode_recovery_point(H264SEIRecoveryPoint *h, GetBitContext *gb, void *logctx)
288 {
289 unsigned recovery_frame_cnt = get_ue_golomb_long(gb);
290
291 if (recovery_frame_cnt >= (1<<MAX_LOG2_MAX_FRAME_NUM)) {
292 av_log(logctx, AV_LOG_ERROR, "recovery_frame_cnt %u is out of range\n", recovery_frame_cnt);
293 return AVERROR_INVALIDDATA;
294 }
295
296 h->recovery_frame_cnt = recovery_frame_cnt;
297 /* 1b exact_match_flag,
298 * 1b broken_link_flag,
299 * 2b changing_slice_group_idc */
300 skip_bits(gb, 4);
301
302 return 0;
303 }
304
decode_buffering_period(H264SEIBufferingPeriod *h, GetBitContext *gb, const H264ParamSets *ps, void *logctx)305 static int decode_buffering_period(H264SEIBufferingPeriod *h, GetBitContext *gb,
306 const H264ParamSets *ps, void *logctx)
307 {
308 unsigned int sps_id;
309 int sched_sel_idx;
310 const SPS *sps;
311
312 sps_id = get_ue_golomb_31(gb);
313 if (sps_id > 31 || !ps->sps_list[sps_id]) {
314 av_log(logctx, AV_LOG_ERROR,
315 "non-existing SPS %d referenced in buffering period\n", sps_id);
316 return sps_id > 31 ? AVERROR_INVALIDDATA : AVERROR_PS_NOT_FOUND;
317 }
318 sps = (const SPS*)ps->sps_list[sps_id]->data;
319
320 // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
321 if (sps->nal_hrd_parameters_present_flag) {
322 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
323 h->initial_cpb_removal_delay[sched_sel_idx] =
324 get_bits_long(gb, sps->initial_cpb_removal_delay_length);
325 // initial_cpb_removal_delay_offset
326 skip_bits(gb, sps->initial_cpb_removal_delay_length);
327 }
328 }
329 if (sps->vcl_hrd_parameters_present_flag) {
330 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
331 h->initial_cpb_removal_delay[sched_sel_idx] =
332 get_bits_long(gb, sps->initial_cpb_removal_delay_length);
333 // initial_cpb_removal_delay_offset
334 skip_bits(gb, sps->initial_cpb_removal_delay_length);
335 }
336 }
337
338 h->present = 1;
339 return 0;
340 }
341
decode_frame_packing_arrangement(H264SEIFramePacking *h, GetBitContext *gb)342 static int decode_frame_packing_arrangement(H264SEIFramePacking *h,
343 GetBitContext *gb)
344 {
345 h->arrangement_id = get_ue_golomb_long(gb);
346 h->arrangement_cancel_flag = get_bits1(gb);
347 h->present = !h->arrangement_cancel_flag;
348
349 if (h->present) {
350 h->arrangement_type = get_bits(gb, 7);
351 h->quincunx_sampling_flag = get_bits1(gb);
352 h->content_interpretation_type = get_bits(gb, 6);
353
354 // spatial_flipping_flag, frame0_flipped_flag, field_views_flag
355 skip_bits(gb, 3);
356 h->current_frame_is_frame0_flag = get_bits1(gb);
357 // frame0_self_contained_flag, frame1_self_contained_flag
358 skip_bits(gb, 2);
359
360 if (!h->quincunx_sampling_flag && h->arrangement_type != 5)
361 skip_bits(gb, 16); // frame[01]_grid_position_[xy]
362 skip_bits(gb, 8); // frame_packing_arrangement_reserved_byte
363 h->arrangement_repetition_period = get_ue_golomb_long(gb);
364 }
365 skip_bits1(gb); // frame_packing_arrangement_extension_flag
366
367 return 0;
368 }
369
decode_display_orientation(H264SEIDisplayOrientation *h, GetBitContext *gb)370 static int decode_display_orientation(H264SEIDisplayOrientation *h,
371 GetBitContext *gb)
372 {
373 h->present = !get_bits1(gb);
374
375 if (h->present) {
376 h->hflip = get_bits1(gb); // hor_flip
377 h->vflip = get_bits1(gb); // ver_flip
378
379 h->anticlockwise_rotation = get_bits(gb, 16);
380 get_ue_golomb_long(gb); // display_orientation_repetition_period
381 skip_bits1(gb); // display_orientation_extension_flag
382 }
383
384 return 0;
385 }
386
decode_green_metadata(H264SEIGreenMetaData *h, GetBitContext *gb)387 static int decode_green_metadata(H264SEIGreenMetaData *h, GetBitContext *gb)
388 {
389 h->green_metadata_type = get_bits(gb, 8);
390
391 if (h->green_metadata_type == 0) {
392 h->period_type = get_bits(gb, 8);
393
394 if (h->period_type == 2)
395 h->num_seconds = get_bits(gb, 16);
396 else if (h->period_type == 3)
397 h->num_pictures = get_bits(gb, 16);
398
399 h->percent_non_zero_macroblocks = get_bits(gb, 8);
400 h->percent_intra_coded_macroblocks = get_bits(gb, 8);
401 h->percent_six_tap_filtering = get_bits(gb, 8);
402 h->percent_alpha_point_deblocking_instance = get_bits(gb, 8);
403
404 } else if (h->green_metadata_type == 1) {
405 h->xsd_metric_type = get_bits(gb, 8);
406 h->xsd_metric_value = get_bits(gb, 16);
407 }
408
409 return 0;
410 }
411
decode_alternative_transfer(H264SEIAlternativeTransfer *h, GetBitContext *gb)412 static int decode_alternative_transfer(H264SEIAlternativeTransfer *h,
413 GetBitContext *gb)
414 {
415 h->present = 1;
416 h->preferred_transfer_characteristics = get_bits(gb, 8);
417 return 0;
418 }
419
decode_film_grain_characteristics(H264SEIFilmGrainCharacteristics *h, GetBitContext *gb)420 static int decode_film_grain_characteristics(H264SEIFilmGrainCharacteristics *h,
421 GetBitContext *gb)
422 {
423 h->present = !get_bits1(gb); // film_grain_characteristics_cancel_flag
424
425 if (h->present) {
426 memset(h, 0, sizeof(*h));
427 h->model_id = get_bits(gb, 2);
428 h->separate_colour_description_present_flag = get_bits1(gb);
429 if (h->separate_colour_description_present_flag) {
430 h->bit_depth_luma = get_bits(gb, 3) + 8;
431 h->bit_depth_chroma = get_bits(gb, 3) + 8;
432 h->full_range = get_bits1(gb);
433 h->color_primaries = get_bits(gb, 8);
434 h->transfer_characteristics = get_bits(gb, 8);
435 h->matrix_coeffs = get_bits(gb, 8);
436 }
437 h->blending_mode_id = get_bits(gb, 2);
438 h->log2_scale_factor = get_bits(gb, 4);
439 for (int c = 0; c < 3; c++)
440 h->comp_model_present_flag[c] = get_bits1(gb);
441 for (int c = 0; c < 3; c++) {
442 if (h->comp_model_present_flag[c]) {
443 h->num_intensity_intervals[c] = get_bits(gb, 8) + 1;
444 h->num_model_values[c] = get_bits(gb, 3) + 1;
445 if (h->num_model_values[c] > 6)
446 return AVERROR_INVALIDDATA;
447 for (int i = 0; i < h->num_intensity_intervals[c]; i++) {
448 h->intensity_interval_lower_bound[c][i] = get_bits(gb, 8);
449 h->intensity_interval_upper_bound[c][i] = get_bits(gb, 8);
450 for (int j = 0; j < h->num_model_values[c]; j++)
451 h->comp_model_value[c][i][j] = get_se_golomb_long(gb);
452 }
453 }
454 }
455 h->repetition_period = get_ue_golomb_long(gb);
456
457 h->present = 1;
458 }
459
460 return 0;
461 }
462
ff_h264_sei_decode(H264SEIContext *h, GetBitContext *gb, const H264ParamSets *ps, void *logctx)463 int ff_h264_sei_decode(H264SEIContext *h, GetBitContext *gb,
464 const H264ParamSets *ps, void *logctx)
465 {
466 int master_ret = 0;
467
468 while (get_bits_left(gb) > 16 && show_bits(gb, 16)) {
469 GetBitContext gb_payload;
470 int type = 0;
471 unsigned size = 0;
472 int ret = 0;
473
474 do {
475 if (get_bits_left(gb) < 8)
476 return AVERROR_INVALIDDATA;
477 type += show_bits(gb, 8);
478 } while (get_bits(gb, 8) == 255);
479
480 do {
481 if (get_bits_left(gb) < 8)
482 return AVERROR_INVALIDDATA;
483 size += show_bits(gb, 8);
484 } while (get_bits(gb, 8) == 255);
485
486 if (size > get_bits_left(gb) / 8) {
487 av_log(logctx, AV_LOG_ERROR, "SEI type %d size %d truncated at %d\n",
488 type, 8*size, get_bits_left(gb));
489 return AVERROR_INVALIDDATA;
490 }
491
492 ret = init_get_bits8(&gb_payload, gb->buffer + get_bits_count(gb) / 8, size);
493 if (ret < 0)
494 return ret;
495
496 switch (type) {
497 case SEI_TYPE_PIC_TIMING: // Picture timing SEI
498 ret = decode_picture_timing(&h->picture_timing, &gb_payload, logctx);
499 break;
500 case SEI_TYPE_USER_DATA_REGISTERED_ITU_T_T35:
501 ret = decode_registered_user_data(h, &gb_payload, logctx, size);
502 break;
503 case SEI_TYPE_USER_DATA_UNREGISTERED:
504 ret = decode_unregistered_user_data(&h->unregistered, &gb_payload, logctx, size);
505 break;
506 case SEI_TYPE_RECOVERY_POINT:
507 ret = decode_recovery_point(&h->recovery_point, &gb_payload, logctx);
508 break;
509 case SEI_TYPE_BUFFERING_PERIOD:
510 ret = decode_buffering_period(&h->buffering_period, &gb_payload, ps, logctx);
511 break;
512 case SEI_TYPE_FRAME_PACKING_ARRANGEMENT:
513 ret = decode_frame_packing_arrangement(&h->frame_packing, &gb_payload);
514 break;
515 case SEI_TYPE_DISPLAY_ORIENTATION:
516 ret = decode_display_orientation(&h->display_orientation, &gb_payload);
517 break;
518 case SEI_TYPE_GREEN_METADATA:
519 ret = decode_green_metadata(&h->green_metadata, &gb_payload);
520 break;
521 case SEI_TYPE_ALTERNATIVE_TRANSFER_CHARACTERISTICS:
522 ret = decode_alternative_transfer(&h->alternative_transfer, &gb_payload);
523 break;
524 case SEI_TYPE_FILM_GRAIN_CHARACTERISTICS:
525 ret = decode_film_grain_characteristics(&h->film_grain_characteristics, &gb_payload);
526 break;
527 default:
528 av_log(logctx, AV_LOG_DEBUG, "unknown SEI type %d\n", type);
529 }
530 if (ret < 0 && ret != AVERROR_PS_NOT_FOUND)
531 return ret;
532 if (ret < 0)
533 master_ret = ret;
534
535 if (get_bits_left(&gb_payload) < 0) {
536 av_log(logctx, AV_LOG_WARNING, "SEI type %d overread by %d bits\n",
537 type, -get_bits_left(&gb_payload));
538 }
539
540 skip_bits_long(gb, 8 * size);
541 }
542
543 return master_ret;
544 }
545
ff_h264_sei_stereo_mode(const H264SEIFramePacking *h)546 const char *ff_h264_sei_stereo_mode(const H264SEIFramePacking *h)
547 {
548 if (h->arrangement_cancel_flag == 0) {
549 switch (h->arrangement_type) {
550 case H264_SEI_FPA_TYPE_CHECKERBOARD:
551 if (h->content_interpretation_type == 2)
552 return "checkerboard_rl";
553 else
554 return "checkerboard_lr";
555 case H264_SEI_FPA_TYPE_INTERLEAVE_COLUMN:
556 if (h->content_interpretation_type == 2)
557 return "col_interleaved_rl";
558 else
559 return "col_interleaved_lr";
560 case H264_SEI_FPA_TYPE_INTERLEAVE_ROW:
561 if (h->content_interpretation_type == 2)
562 return "row_interleaved_rl";
563 else
564 return "row_interleaved_lr";
565 case H264_SEI_FPA_TYPE_SIDE_BY_SIDE:
566 if (h->content_interpretation_type == 2)
567 return "right_left";
568 else
569 return "left_right";
570 case H264_SEI_FPA_TYPE_TOP_BOTTOM:
571 if (h->content_interpretation_type == 2)
572 return "bottom_top";
573 else
574 return "top_bottom";
575 case H264_SEI_FPA_TYPE_INTERLEAVE_TEMPORAL:
576 if (h->content_interpretation_type == 2)
577 return "block_rl";
578 else
579 return "block_lr";
580 case H264_SEI_FPA_TYPE_2D:
581 default:
582 return "mono";
583 }
584 } else if (h->arrangement_cancel_flag == 1) {
585 return "mono";
586 } else {
587 return NULL;
588 }
589 }
590