1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#include "bytestream.h"
20#include "get_bits.h"
21#include "golomb.h"
22#include "h264.h"
23#include "h264pred.h"
24#include "h264_parse.h"
25#include "h264_ps.h"
26#include "h2645_parse.h"
27#include "mpegutils.h"
28
29int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
30                              const int *ref_count, int slice_type_nos,
31                              H264PredWeightTable *pwt,
32                              int picture_structure, void *logctx)
33{
34    int list, i, j;
35    int luma_def, chroma_def;
36
37    pwt->use_weight             = 0;
38    pwt->use_weight_chroma      = 0;
39
40    pwt->luma_log2_weight_denom = get_ue_golomb_31(gb);
41    if (pwt->luma_log2_weight_denom > 7U) {
42        av_log(logctx, AV_LOG_ERROR, "luma_log2_weight_denom %d is out of range\n", pwt->luma_log2_weight_denom);
43        pwt->luma_log2_weight_denom = 0;
44    }
45    luma_def = 1 << pwt->luma_log2_weight_denom;
46
47    if (sps->chroma_format_idc) {
48        pwt->chroma_log2_weight_denom = get_ue_golomb_31(gb);
49        if (pwt->chroma_log2_weight_denom > 7U) {
50            av_log(logctx, AV_LOG_ERROR, "chroma_log2_weight_denom %d is out of range\n", pwt->chroma_log2_weight_denom);
51            pwt->chroma_log2_weight_denom = 0;
52        }
53        chroma_def = 1 << pwt->chroma_log2_weight_denom;
54    }
55
56    for (list = 0; list < 2; list++) {
57        pwt->luma_weight_flag[list]   = 0;
58        pwt->chroma_weight_flag[list] = 0;
59        for (i = 0; i < ref_count[list]; i++) {
60            int luma_weight_flag, chroma_weight_flag;
61
62            luma_weight_flag = get_bits1(gb);
63            if (luma_weight_flag) {
64                pwt->luma_weight[i][list][0] = get_se_golomb(gb);
65                pwt->luma_weight[i][list][1] = get_se_golomb(gb);
66                if ((int8_t)pwt->luma_weight[i][list][0] != pwt->luma_weight[i][list][0] ||
67                    (int8_t)pwt->luma_weight[i][list][1] != pwt->luma_weight[i][list][1])
68                    goto out_range_weight;
69                if (pwt->luma_weight[i][list][0] != luma_def ||
70                    pwt->luma_weight[i][list][1] != 0) {
71                    pwt->use_weight             = 1;
72                    pwt->luma_weight_flag[list] = 1;
73                }
74            } else {
75                pwt->luma_weight[i][list][0] = luma_def;
76                pwt->luma_weight[i][list][1] = 0;
77            }
78
79            if (sps->chroma_format_idc) {
80                chroma_weight_flag = get_bits1(gb);
81                if (chroma_weight_flag) {
82                    int j;
83                    for (j = 0; j < 2; j++) {
84                        pwt->chroma_weight[i][list][j][0] = get_se_golomb(gb);
85                        pwt->chroma_weight[i][list][j][1] = get_se_golomb(gb);
86                        if ((int8_t)pwt->chroma_weight[i][list][j][0] != pwt->chroma_weight[i][list][j][0] ||
87                            (int8_t)pwt->chroma_weight[i][list][j][1] != pwt->chroma_weight[i][list][j][1]) {
88                            pwt->chroma_weight[i][list][j][0] = chroma_def;
89                            pwt->chroma_weight[i][list][j][1] = 0;
90                            goto out_range_weight;
91                        }
92                        if (pwt->chroma_weight[i][list][j][0] != chroma_def ||
93                            pwt->chroma_weight[i][list][j][1] != 0) {
94                            pwt->use_weight_chroma        = 1;
95                            pwt->chroma_weight_flag[list] = 1;
96                        }
97                    }
98                } else {
99                    int j;
100                    for (j = 0; j < 2; j++) {
101                        pwt->chroma_weight[i][list][j][0] = chroma_def;
102                        pwt->chroma_weight[i][list][j][1] = 0;
103                    }
104                }
105            }
106
107            // for MBAFF
108            if (picture_structure == PICT_FRAME) {
109                pwt->luma_weight[16 + 2 * i][list][0] = pwt->luma_weight[16 + 2 * i + 1][list][0] = pwt->luma_weight[i][list][0];
110                pwt->luma_weight[16 + 2 * i][list][1] = pwt->luma_weight[16 + 2 * i + 1][list][1] = pwt->luma_weight[i][list][1];
111                if (sps->chroma_format_idc) {
112                    for (j = 0; j < 2; j++) {
113                        pwt->chroma_weight[16 + 2 * i][list][j][0] = pwt->chroma_weight[16 + 2 * i + 1][list][j][0] = pwt->chroma_weight[i][list][j][0];
114                        pwt->chroma_weight[16 + 2 * i][list][j][1] = pwt->chroma_weight[16 + 2 * i + 1][list][j][1] = pwt->chroma_weight[i][list][j][1];
115                    }
116                }
117            }
118        }
119        if (slice_type_nos != AV_PICTURE_TYPE_B)
120            break;
121    }
122    pwt->use_weight = pwt->use_weight || pwt->use_weight_chroma;
123    return 0;
124out_range_weight:
125    avpriv_request_sample(logctx, "Out of range weight");
126    return AVERROR_INVALIDDATA;
127}
128
129/**
130 * Check if the top & left blocks are available if needed and
131 * change the dc mode so it only uses the available blocks.
132 */
133int ff_h264_check_intra4x4_pred_mode(int8_t *pred_mode_cache, void *logctx,
134                                     int top_samples_available, int left_samples_available)
135{
136    static const int8_t top[12] = {
137        -1, 0, LEFT_DC_PRED, -1, -1, -1, -1, -1, 0
138    };
139    static const int8_t left[12] = {
140        0, -1, TOP_DC_PRED, 0, -1, -1, -1, 0, -1, DC_128_PRED
141    };
142    int i;
143
144    if (!(top_samples_available & 0x8000)) {
145        for (i = 0; i < 4; i++) {
146            int status = top[pred_mode_cache[scan8[0] + i]];
147            if (status < 0) {
148                av_log(logctx, AV_LOG_ERROR,
149                       "top block unavailable for requested intra mode %d\n",
150                       status);
151                return AVERROR_INVALIDDATA;
152            } else if (status) {
153                pred_mode_cache[scan8[0] + i] = status;
154            }
155        }
156    }
157
158    if ((left_samples_available & 0x8888) != 0x8888) {
159        static const int mask[4] = { 0x8000, 0x2000, 0x80, 0x20 };
160        for (i = 0; i < 4; i++)
161            if (!(left_samples_available & mask[i])) {
162                int status = left[pred_mode_cache[scan8[0] + 8 * i]];
163                if (status < 0) {
164                    av_log(logctx, AV_LOG_ERROR,
165                           "left block unavailable for requested intra4x4 mode %d\n",
166                           status);
167                    return AVERROR_INVALIDDATA;
168                } else if (status) {
169                    pred_mode_cache[scan8[0] + 8 * i] = status;
170                }
171            }
172    }
173
174    return 0;
175}
176
177/**
178 * Check if the top & left blocks are available if needed and
179 * change the dc mode so it only uses the available blocks.
180 */
181int ff_h264_check_intra_pred_mode(void *logctx, int top_samples_available,
182                                  int left_samples_available,
183                                  int mode, int is_chroma)
184{
185    static const int8_t top[4]  = { LEFT_DC_PRED8x8, 1, -1, -1 };
186    static const int8_t left[5] = { TOP_DC_PRED8x8, -1,  2, -1, DC_128_PRED8x8 };
187
188    if (mode > 3U) {
189        av_log(logctx, AV_LOG_ERROR,
190               "out of range intra chroma pred mode\n");
191        return AVERROR_INVALIDDATA;
192    }
193
194    if (!(top_samples_available & 0x8000)) {
195        mode = top[mode];
196        if (mode < 0) {
197            av_log(logctx, AV_LOG_ERROR,
198                   "top block unavailable for requested intra mode\n");
199            return AVERROR_INVALIDDATA;
200        }
201    }
202
203    if ((left_samples_available & 0x8080) != 0x8080) {
204        mode = left[mode];
205        if (mode < 0) {
206            av_log(logctx, AV_LOG_ERROR,
207                   "left block unavailable for requested intra mode\n");
208            return AVERROR_INVALIDDATA;
209        }
210        if (is_chroma && (left_samples_available & 0x8080)) {
211            // mad cow disease mode, aka MBAFF + constrained_intra_pred
212            mode = ALZHEIMER_DC_L0T_PRED8x8 +
213                   (!(left_samples_available & 0x8000)) +
214                   2 * (mode == DC_128_PRED8x8);
215        }
216    }
217
218    return mode;
219}
220
221int ff_h264_parse_ref_count(int *plist_count, int ref_count[2],
222                            GetBitContext *gb, const PPS *pps,
223                            int slice_type_nos, int picture_structure, void *logctx)
224{
225    int list_count;
226    int num_ref_idx_active_override_flag;
227
228    // set defaults, might be overridden a few lines later
229    ref_count[0] = pps->ref_count[0];
230    ref_count[1] = pps->ref_count[1];
231
232    if (slice_type_nos != AV_PICTURE_TYPE_I) {
233        unsigned max[2];
234        max[0] = max[1] = picture_structure == PICT_FRAME ? 15 : 31;
235
236        num_ref_idx_active_override_flag = get_bits1(gb);
237
238        if (num_ref_idx_active_override_flag) {
239            ref_count[0] = get_ue_golomb(gb) + 1;
240            if (slice_type_nos == AV_PICTURE_TYPE_B) {
241                ref_count[1] = get_ue_golomb(gb) + 1;
242            } else
243                // full range is spec-ok in this case, even for frames
244                ref_count[1] = 1;
245        }
246
247        if (slice_type_nos == AV_PICTURE_TYPE_B)
248            list_count = 2;
249        else
250            list_count = 1;
251
252        if (ref_count[0] - 1 > max[0] || (list_count == 2 && (ref_count[1] - 1 > max[1]))) {
253            av_log(logctx, AV_LOG_ERROR, "reference overflow %u > %u or %u > %u\n",
254                   ref_count[0] - 1, max[0], ref_count[1] - 1, max[1]);
255            ref_count[0] = ref_count[1] = 0;
256            *plist_count = 0;
257            goto fail;
258        } else if (ref_count[1] - 1 > max[1]) {
259            av_log(logctx, AV_LOG_DEBUG, "reference overflow %u > %u \n",
260                   ref_count[1] - 1, max[1]);
261            ref_count[1] = 0;
262        }
263
264    } else {
265        list_count   = 0;
266        ref_count[0] = ref_count[1] = 0;
267    }
268
269    *plist_count = list_count;
270
271    return 0;
272fail:
273    *plist_count = 0;
274    ref_count[0] = 0;
275    ref_count[1] = 0;
276    return AVERROR_INVALIDDATA;
277}
278
279int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
280                     const SPS *sps, H264POCContext *pc,
281                     int picture_structure, int nal_ref_idc)
282{
283    const int max_frame_num = 1 << sps->log2_max_frame_num;
284    int64_t field_poc[2];
285
286    pc->frame_num_offset = pc->prev_frame_num_offset;
287    if (pc->frame_num < pc->prev_frame_num)
288        pc->frame_num_offset += max_frame_num;
289
290    if (sps->poc_type == 0) {
291        const int max_poc_lsb = 1 << sps->log2_max_poc_lsb;
292        if (pc->prev_poc_lsb < 0)
293            pc->prev_poc_lsb =  pc->poc_lsb;
294
295        if (pc->poc_lsb < pc->prev_poc_lsb &&
296            pc->prev_poc_lsb - pc->poc_lsb >= max_poc_lsb / 2)
297            pc->poc_msb = pc->prev_poc_msb + max_poc_lsb;
298        else if (pc->poc_lsb > pc->prev_poc_lsb &&
299                 pc->prev_poc_lsb - pc->poc_lsb < -max_poc_lsb / 2)
300            pc->poc_msb = pc->prev_poc_msb - max_poc_lsb;
301        else
302            pc->poc_msb = pc->prev_poc_msb;
303        field_poc[0] =
304        field_poc[1] = pc->poc_msb + pc->poc_lsb;
305        if (picture_structure == PICT_FRAME)
306            field_poc[1] += pc->delta_poc_bottom;
307    } else if (sps->poc_type == 1) {
308        int abs_frame_num;
309        int64_t expected_delta_per_poc_cycle, expectedpoc;
310        int i;
311
312        if (sps->poc_cycle_length != 0)
313            abs_frame_num = pc->frame_num_offset + pc->frame_num;
314        else
315            abs_frame_num = 0;
316
317        if (nal_ref_idc == 0 && abs_frame_num > 0)
318            abs_frame_num--;
319
320        expected_delta_per_poc_cycle = 0;
321        for (i = 0; i < sps->poc_cycle_length; i++)
322            // FIXME integrate during sps parse
323            expected_delta_per_poc_cycle += sps->offset_for_ref_frame[i];
324
325        if (abs_frame_num > 0) {
326            int poc_cycle_cnt          = (abs_frame_num - 1) / sps->poc_cycle_length;
327            int frame_num_in_poc_cycle = (abs_frame_num - 1) % sps->poc_cycle_length;
328
329            expectedpoc = poc_cycle_cnt * expected_delta_per_poc_cycle;
330            for (i = 0; i <= frame_num_in_poc_cycle; i++)
331                expectedpoc = expectedpoc + sps->offset_for_ref_frame[i];
332        } else
333            expectedpoc = 0;
334
335        if (nal_ref_idc == 0)
336            expectedpoc = expectedpoc + sps->offset_for_non_ref_pic;
337
338        field_poc[0] = expectedpoc + pc->delta_poc[0];
339        field_poc[1] = field_poc[0] + sps->offset_for_top_to_bottom_field;
340
341        if (picture_structure == PICT_FRAME)
342            field_poc[1] += pc->delta_poc[1];
343    } else {
344        int poc = 2 * (pc->frame_num_offset + pc->frame_num);
345
346        if (!nal_ref_idc)
347            poc--;
348
349        field_poc[0] = poc;
350        field_poc[1] = poc;
351    }
352
353    if (   field_poc[0] != (int)field_poc[0]
354        || field_poc[1] != (int)field_poc[1])
355        return AVERROR_INVALIDDATA;
356
357    if (picture_structure != PICT_BOTTOM_FIELD)
358        pic_field_poc[0] = field_poc[0];
359    if (picture_structure != PICT_TOP_FIELD)
360        pic_field_poc[1] = field_poc[1];
361    *pic_poc = FFMIN(pic_field_poc[0], pic_field_poc[1]);
362
363    return 0;
364}
365
366static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
367                               int is_avc, void *logctx)
368{
369    H2645Packet pkt = { 0 };
370    int i, ret = 0;
371
372    ret = ff_h2645_packet_split(&pkt, data, size, logctx, is_avc, 2, AV_CODEC_ID_H264, 1, 0);
373    if (ret < 0) {
374        ret = 0;
375        goto fail;
376    }
377
378    for (i = 0; i < pkt.nb_nals; i++) {
379        H2645NAL *nal = &pkt.nals[i];
380        switch (nal->type) {
381        case H264_NAL_SPS: {
382            GetBitContext tmp_gb = nal->gb;
383            ret = ff_h264_decode_seq_parameter_set(&tmp_gb, logctx, ps, 0);
384            if (ret >= 0)
385                break;
386            av_log(logctx, AV_LOG_DEBUG,
387                   "SPS decoding failure, trying again with the complete NAL\n");
388            init_get_bits8(&tmp_gb, nal->raw_data + 1, nal->raw_size - 1);
389            ret = ff_h264_decode_seq_parameter_set(&tmp_gb, logctx, ps, 0);
390            if (ret >= 0)
391                break;
392            ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps, 1);
393            if (ret < 0)
394                goto fail;
395            break;
396        }
397        case H264_NAL_PPS:
398            ret = ff_h264_decode_picture_parameter_set(&nal->gb, logctx, ps,
399                                                       nal->size_bits);
400            if (ret < 0)
401                goto fail;
402            break;
403        default:
404            av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n",
405                   nal->type);
406            break;
407        }
408    }
409
410fail:
411    ff_h2645_packet_uninit(&pkt);
412    return ret;
413}
414
415/* There are (invalid) samples in the wild with mp4-style extradata, where the
416 * parameter sets are stored unescaped (i.e. as RBSP).
417 * This function catches the parameter set decoding failure and tries again
418 * after escaping it */
419static int decode_extradata_ps_mp4(const uint8_t *buf, int buf_size, H264ParamSets *ps,
420                                   int err_recognition, void *logctx)
421{
422    int ret;
423
424    ret = decode_extradata_ps(buf, buf_size, ps, 1, logctx);
425    if (ret < 0 && !(err_recognition & AV_EF_EXPLODE)) {
426        GetByteContext gbc;
427        PutByteContext pbc;
428        uint8_t *escaped_buf;
429        int escaped_buf_size;
430
431        av_log(logctx, AV_LOG_WARNING,
432               "SPS decoding failure, trying again after escaping the NAL\n");
433
434        if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3)
435            return AVERROR(ERANGE);
436        escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE;
437        escaped_buf = av_mallocz(escaped_buf_size);
438        if (!escaped_buf)
439            return AVERROR(ENOMEM);
440
441        bytestream2_init(&gbc, buf, buf_size);
442        bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size);
443
444        while (bytestream2_get_bytes_left(&gbc)) {
445            if (bytestream2_get_bytes_left(&gbc) >= 3 &&
446                bytestream2_peek_be24(&gbc) <= 3) {
447                bytestream2_put_be24(&pbc, 3);
448                bytestream2_skip(&gbc, 2);
449            } else
450                bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
451        }
452
453        escaped_buf_size = bytestream2_tell_p(&pbc);
454        AV_WB16(escaped_buf, escaped_buf_size - 2);
455
456        (void)decode_extradata_ps(escaped_buf, escaped_buf_size, ps, 1, logctx);
457        // lorex.mp4 decodes ok even with extradata decoding failing
458        av_freep(&escaped_buf);
459    }
460
461    return 0;
462}
463
464int ff_h264_decode_extradata(const uint8_t *data, int size, H264ParamSets *ps,
465                             int *is_avc, int *nal_length_size,
466                             int err_recognition, void *logctx)
467{
468    int ret;
469
470    if (!data || size <= 0)
471        return -1;
472
473    if (data[0] == 1) {
474        int i, cnt, nalsize;
475        const uint8_t *p = data;
476
477        *is_avc = 1;
478
479        if (size < 7) {
480            av_log(logctx, AV_LOG_ERROR, "avcC %d too short\n", size);
481            return AVERROR_INVALIDDATA;
482        }
483
484        // Decode sps from avcC
485        cnt = *(p + 5) & 0x1f; // Number of sps
486        p  += 6;
487        for (i = 0; i < cnt; i++) {
488            nalsize = AV_RB16(p) + 2;
489            if (nalsize > size - (p - data))
490                return AVERROR_INVALIDDATA;
491            ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
492            if (ret < 0) {
493                av_log(logctx, AV_LOG_ERROR,
494                       "Decoding sps %d from avcC failed\n", i);
495                return ret;
496            }
497            p += nalsize;
498        }
499        // Decode pps from avcC
500        cnt = *(p++); // Number of pps
501        for (i = 0; i < cnt; i++) {
502            nalsize = AV_RB16(p) + 2;
503            if (nalsize > size - (p - data))
504                return AVERROR_INVALIDDATA;
505            ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
506            if (ret < 0) {
507                av_log(logctx, AV_LOG_ERROR,
508                       "Decoding pps %d from avcC failed\n", i);
509                return ret;
510            }
511            p += nalsize;
512        }
513        // Store right nal length size that will be used to parse all other nals
514        *nal_length_size = (data[4] & 0x03) + 1;
515    } else {
516        *is_avc = 0;
517        ret = decode_extradata_ps(data, size, ps, 0, logctx);
518        if (ret < 0)
519            return ret;
520    }
521    return size;
522}
523
524/**
525 * Compute profile from profile_idc and constraint_set?_flags.
526 *
527 * @param sps SPS
528 *
529 * @return profile as defined by FF_PROFILE_H264_*
530 */
531int ff_h264_get_profile(const SPS *sps)
532{
533    int profile = sps->profile_idc;
534
535    switch (sps->profile_idc) {
536    case FF_PROFILE_H264_BASELINE:
537        // constraint_set1_flag set to 1
538        profile |= (sps->constraint_set_flags & 1 << 1) ? FF_PROFILE_H264_CONSTRAINED : 0;
539        break;
540    case FF_PROFILE_H264_HIGH_10:
541    case FF_PROFILE_H264_HIGH_422:
542    case FF_PROFILE_H264_HIGH_444_PREDICTIVE:
543        // constraint_set3_flag set to 1
544        profile |= (sps->constraint_set_flags & 1 << 3) ? FF_PROFILE_H264_INTRA : 0;
545        break;
546    }
547
548    return profile;
549}
550