1/*
2 * H.264/HEVC common parsing code
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include <string.h>
22
23#include "config.h"
24
25#include "libavutil/intmath.h"
26#include "libavutil/intreadwrite.h"
27#include "libavutil/mem.h"
28
29#include "bytestream.h"
30#include "hevc.h"
31#include "h264.h"
32#include "h2645_parse.h"
33
34int ff_h2645_extract_rbsp(const uint8_t *src, int length,
35                          H2645RBSP *rbsp, H2645NAL *nal, int small_padding)
36{
37    int i, si, di;
38    uint8_t *dst;
39
40    nal->skipped_bytes = 0;
41#define STARTCODE_TEST                                                  \
42        if (i + 2 < length && src[i + 1] == 0 && src[i + 2] <= 3) {     \
43            if (src[i + 2] != 3 && src[i + 2] != 0) {                   \
44                /* startcode, so we must be past the end */             \
45                length = i;                                             \
46            }                                                           \
47            break;                                                      \
48        }
49#if HAVE_FAST_UNALIGNED
50#define FIND_FIRST_ZERO                                                 \
51        if (i > 0 && !src[i])                                           \
52            i--;                                                        \
53        while (src[i])                                                  \
54            i++
55#if HAVE_FAST_64BIT
56    for (i = 0; i + 1 < length; i += 9) {
57        if (!((~AV_RN64(src + i) &
58               (AV_RN64(src + i) - 0x0100010001000101ULL)) &
59              0x8000800080008080ULL))
60            continue;
61        FIND_FIRST_ZERO;
62        STARTCODE_TEST;
63        i -= 7;
64    }
65#else
66    for (i = 0; i + 1 < length; i += 5) {
67        if (!((~AV_RN32(src + i) &
68               (AV_RN32(src + i) - 0x01000101U)) &
69              0x80008080U))
70            continue;
71        FIND_FIRST_ZERO;
72        STARTCODE_TEST;
73        i -= 3;
74    }
75#endif /* HAVE_FAST_64BIT */
76#else
77    for (i = 0; i + 1 < length; i += 2) {
78        if (src[i])
79            continue;
80        if (i > 0 && src[i - 1] == 0)
81            i--;
82        STARTCODE_TEST;
83    }
84#endif /* HAVE_FAST_UNALIGNED */
85
86    if (i >= length - 1 && small_padding) { // no escaped 0
87        nal->data     =
88        nal->raw_data = src;
89        nal->size     =
90        nal->raw_size = length;
91        return length;
92    } else if (i > length)
93        i = length;
94
95    dst = &rbsp->rbsp_buffer[rbsp->rbsp_buffer_size];
96
97    memcpy(dst, src, i);
98    si = di = i;
99    while (si + 2 < length) {
100        // remove escapes (very rare 1:2^22)
101        if (src[si + 2] > 3) {
102            dst[di++] = src[si++];
103            dst[di++] = src[si++];
104        } else if (src[si] == 0 && src[si + 1] == 0 && src[si + 2] != 0) {
105            if (src[si + 2] == 3) { // escape
106                dst[di++] = 0;
107                dst[di++] = 0;
108                si       += 3;
109
110                if (nal->skipped_bytes_pos) {
111                    nal->skipped_bytes++;
112                    if (nal->skipped_bytes_pos_size < nal->skipped_bytes) {
113                        nal->skipped_bytes_pos_size *= 2;
114                        av_assert0(nal->skipped_bytes_pos_size >= nal->skipped_bytes);
115                        av_reallocp_array(&nal->skipped_bytes_pos,
116                                nal->skipped_bytes_pos_size,
117                                sizeof(*nal->skipped_bytes_pos));
118                        if (!nal->skipped_bytes_pos) {
119                            nal->skipped_bytes_pos_size = 0;
120                            return AVERROR(ENOMEM);
121                        }
122                    }
123                    if (nal->skipped_bytes_pos)
124                        nal->skipped_bytes_pos[nal->skipped_bytes-1] = di - 1;
125                }
126                continue;
127            } else // next start code
128                goto nsc;
129        }
130
131        dst[di++] = src[si++];
132    }
133    while (si < length)
134        dst[di++] = src[si++];
135
136nsc:
137    memset(dst + di, 0, AV_INPUT_BUFFER_PADDING_SIZE);
138
139    nal->data = dst;
140    nal->size = di;
141    nal->raw_data = src;
142    nal->raw_size = si;
143    rbsp->rbsp_buffer_size += si;
144
145    return si;
146}
147
148static const char *const hevc_nal_type_name[64] = {
149    "TRAIL_N", // HEVC_NAL_TRAIL_N
150    "TRAIL_R", // HEVC_NAL_TRAIL_R
151    "TSA_N", // HEVC_NAL_TSA_N
152    "TSA_R", // HEVC_NAL_TSA_R
153    "STSA_N", // HEVC_NAL_STSA_N
154    "STSA_R", // HEVC_NAL_STSA_R
155    "RADL_N", // HEVC_NAL_RADL_N
156    "RADL_R", // HEVC_NAL_RADL_R
157    "RASL_N", // HEVC_NAL_RASL_N
158    "RASL_R", // HEVC_NAL_RASL_R
159    "RSV_VCL_N10", // HEVC_NAL_VCL_N10
160    "RSV_VCL_R11", // HEVC_NAL_VCL_R11
161    "RSV_VCL_N12", // HEVC_NAL_VCL_N12
162    "RSV_VLC_R13", // HEVC_NAL_VCL_R13
163    "RSV_VCL_N14", // HEVC_NAL_VCL_N14
164    "RSV_VCL_R15", // HEVC_NAL_VCL_R15
165    "BLA_W_LP", // HEVC_NAL_BLA_W_LP
166    "BLA_W_RADL", // HEVC_NAL_BLA_W_RADL
167    "BLA_N_LP", // HEVC_NAL_BLA_N_LP
168    "IDR_W_RADL", // HEVC_NAL_IDR_W_RADL
169    "IDR_N_LP", // HEVC_NAL_IDR_N_LP
170    "CRA_NUT", // HEVC_NAL_CRA_NUT
171    "RSV_IRAP_VCL22", // HEVC_NAL_RSV_IRAP_VCL22
172    "RSV_IRAP_VCL23", // HEVC_NAL_RSV_IRAP_VCL23
173    "RSV_VCL24", // HEVC_NAL_RSV_VCL24
174    "RSV_VCL25", // HEVC_NAL_RSV_VCL25
175    "RSV_VCL26", // HEVC_NAL_RSV_VCL26
176    "RSV_VCL27", // HEVC_NAL_RSV_VCL27
177    "RSV_VCL28", // HEVC_NAL_RSV_VCL28
178    "RSV_VCL29", // HEVC_NAL_RSV_VCL29
179    "RSV_VCL30", // HEVC_NAL_RSV_VCL30
180    "RSV_VCL31", // HEVC_NAL_RSV_VCL31
181    "VPS", // HEVC_NAL_VPS
182    "SPS", // HEVC_NAL_SPS
183    "PPS", // HEVC_NAL_PPS
184    "AUD", // HEVC_NAL_AUD
185    "EOS_NUT", // HEVC_NAL_EOS_NUT
186    "EOB_NUT", // HEVC_NAL_EOB_NUT
187    "FD_NUT", // HEVC_NAL_FD_NUT
188    "SEI_PREFIX", // HEVC_NAL_SEI_PREFIX
189    "SEI_SUFFIX", // HEVC_NAL_SEI_SUFFIX
190    "RSV_NVCL41", // HEVC_NAL_RSV_NVCL41
191    "RSV_NVCL42", // HEVC_NAL_RSV_NVCL42
192    "RSV_NVCL43", // HEVC_NAL_RSV_NVCL43
193    "RSV_NVCL44", // HEVC_NAL_RSV_NVCL44
194    "RSV_NVCL45", // HEVC_NAL_RSV_NVCL45
195    "RSV_NVCL46", // HEVC_NAL_RSV_NVCL46
196    "RSV_NVCL47", // HEVC_NAL_RSV_NVCL47
197    "UNSPEC48", // HEVC_NAL_UNSPEC48
198    "UNSPEC49", // HEVC_NAL_UNSPEC49
199    "UNSPEC50", // HEVC_NAL_UNSPEC50
200    "UNSPEC51", // HEVC_NAL_UNSPEC51
201    "UNSPEC52", // HEVC_NAL_UNSPEC52
202    "UNSPEC53", // HEVC_NAL_UNSPEC53
203    "UNSPEC54", // HEVC_NAL_UNSPEC54
204    "UNSPEC55", // HEVC_NAL_UNSPEC55
205    "UNSPEC56", // HEVC_NAL_UNSPEC56
206    "UNSPEC57", // HEVC_NAL_UNSPEC57
207    "UNSPEC58", // HEVC_NAL_UNSPEC58
208    "UNSPEC59", // HEVC_NAL_UNSPEC59
209    "UNSPEC60", // HEVC_NAL_UNSPEC60
210    "UNSPEC61", // HEVC_NAL_UNSPEC61
211    "UNSPEC62", // HEVC_NAL_UNSPEC62
212    "UNSPEC63", // HEVC_NAL_UNSPEC63
213};
214
215static const char *hevc_nal_unit_name(int nal_type)
216{
217    av_assert0(nal_type >= 0 && nal_type < 64);
218    return hevc_nal_type_name[nal_type];
219}
220
221static const char *const h264_nal_type_name[32] = {
222    "Unspecified 0", //H264_NAL_UNSPECIFIED
223    "Coded slice of a non-IDR picture", // H264_NAL_SLICE
224    "Coded slice data partition A", // H264_NAL_DPA
225    "Coded slice data partition B", // H264_NAL_DPB
226    "Coded slice data partition C", // H264_NAL_DPC
227    "IDR", // H264_NAL_IDR_SLICE
228    "SEI", // H264_NAL_SEI
229    "SPS", // H264_NAL_SPS
230    "PPS", // H264_NAL_PPS
231    "AUD", // H264_NAL_AUD
232    "End of sequence", // H264_NAL_END_SEQUENCE
233    "End of stream", // H264_NAL_END_STREAM
234    "Filler data", // H264_NAL_FILLER_DATA
235    "SPS extension", // H264_NAL_SPS_EXT
236    "Prefix", // H264_NAL_PREFIX
237    "Subset SPS", // H264_NAL_SUB_SPS
238    "Depth parameter set", // H264_NAL_DPS
239    "Reserved 17", // H264_NAL_RESERVED17
240    "Reserved 18", // H264_NAL_RESERVED18
241    "Auxiliary coded picture without partitioning", // H264_NAL_AUXILIARY_SLICE
242    "Slice extension", // H264_NAL_EXTEN_SLICE
243    "Slice extension for a depth view or a 3D-AVC texture view", // H264_NAL_DEPTH_EXTEN_SLICE
244    "Reserved 22", // H264_NAL_RESERVED22
245    "Reserved 23", // H264_NAL_RESERVED23
246    "Unspecified 24", // H264_NAL_UNSPECIFIED24
247    "Unspecified 25", // H264_NAL_UNSPECIFIED25
248    "Unspecified 26", // H264_NAL_UNSPECIFIED26
249    "Unspecified 27", // H264_NAL_UNSPECIFIED27
250    "Unspecified 28", // H264_NAL_UNSPECIFIED28
251    "Unspecified 29", // H264_NAL_UNSPECIFIED29
252    "Unspecified 30", // H264_NAL_UNSPECIFIED30
253    "Unspecified 31", // H264_NAL_UNSPECIFIED31
254};
255
256static const char *h264_nal_unit_name(int nal_type)
257{
258    av_assert0(nal_type >= 0 && nal_type < 32);
259    return h264_nal_type_name[nal_type];
260}
261
262static int get_bit_length(H2645NAL *nal, int min_size, int skip_trailing_zeros)
263{
264    int size = nal->size;
265    int trailing_padding = 0;
266
267    while (skip_trailing_zeros && size > 0 && nal->data[size - 1] == 0)
268        size--;
269
270    if (!size)
271        return 0;
272
273    if (size <= min_size) {
274        if (nal->size < min_size)
275            return AVERROR_INVALIDDATA;
276        size = min_size;
277    } else {
278        int v = nal->data[size - 1];
279        /* remove the stop bit and following trailing zeros,
280         * or nothing for damaged bitstreams */
281        if (v)
282            trailing_padding = ff_ctz(v) + 1;
283    }
284
285    if (size > INT_MAX / 8)
286        return AVERROR(ERANGE);
287    size *= 8;
288
289    return size - trailing_padding;
290}
291
292/**
293 * @return AVERROR_INVALIDDATA if the packet is not a valid NAL unit,
294 * 0 otherwise
295 */
296static int hevc_parse_nal_header(H2645NAL *nal, void *logctx)
297{
298    GetBitContext *gb = &nal->gb;
299
300    if (get_bits1(gb) != 0)
301        return AVERROR_INVALIDDATA;
302
303    nal->type = get_bits(gb, 6);
304
305    nal->nuh_layer_id = get_bits(gb, 6);
306    nal->temporal_id = get_bits(gb, 3) - 1;
307    if (nal->temporal_id < 0)
308        return AVERROR_INVALIDDATA;
309
310    av_log(logctx, AV_LOG_DEBUG,
311           "nal_unit_type: %d(%s), nuh_layer_id: %d, temporal_id: %d\n",
312           nal->type, hevc_nal_unit_name(nal->type), nal->nuh_layer_id, nal->temporal_id);
313
314    return 0;
315}
316
317static int h264_parse_nal_header(H2645NAL *nal, void *logctx)
318{
319    GetBitContext *gb = &nal->gb;
320
321    if (get_bits1(gb) != 0)
322        return AVERROR_INVALIDDATA;
323
324    nal->ref_idc = get_bits(gb, 2);
325    nal->type    = get_bits(gb, 5);
326
327    av_log(logctx, AV_LOG_DEBUG,
328           "nal_unit_type: %d(%s), nal_ref_idc: %d\n",
329           nal->type, h264_nal_unit_name(nal->type), nal->ref_idc);
330
331    return 0;
332}
333
334static int find_next_start_code(const uint8_t *buf, const uint8_t *next_avc)
335{
336    int i = 0;
337
338    if (buf + 3 >= next_avc)
339        return next_avc - buf;
340
341    while (buf + i + 3 < next_avc) {
342        if (buf[i] == 0 && buf[i + 1] == 0 && buf[i + 2] == 1)
343            break;
344        i++;
345    }
346    return i + 3;
347}
348
349static void alloc_rbsp_buffer(H2645RBSP *rbsp, unsigned int size, int use_ref)
350{
351    int min_size = size;
352
353    if (size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
354        goto fail;
355    size += AV_INPUT_BUFFER_PADDING_SIZE;
356
357    if (rbsp->rbsp_buffer_alloc_size >= size &&
358        (!rbsp->rbsp_buffer_ref || av_buffer_is_writable(rbsp->rbsp_buffer_ref))) {
359        av_assert0(rbsp->rbsp_buffer);
360        memset(rbsp->rbsp_buffer + min_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
361        return;
362    }
363
364    size = FFMIN(size + size / 16 + 32, INT_MAX);
365
366    if (rbsp->rbsp_buffer_ref)
367        av_buffer_unref(&rbsp->rbsp_buffer_ref);
368    else
369        av_free(rbsp->rbsp_buffer);
370
371    rbsp->rbsp_buffer = av_mallocz(size);
372    if (!rbsp->rbsp_buffer)
373        goto fail;
374    rbsp->rbsp_buffer_alloc_size = size;
375
376    if (use_ref) {
377        rbsp->rbsp_buffer_ref = av_buffer_create(rbsp->rbsp_buffer, size,
378                                                 NULL, NULL, 0);
379        if (!rbsp->rbsp_buffer_ref)
380            goto fail;
381    }
382
383    return;
384
385fail:
386    rbsp->rbsp_buffer_alloc_size = 0;
387    if (rbsp->rbsp_buffer_ref) {
388        av_buffer_unref(&rbsp->rbsp_buffer_ref);
389        rbsp->rbsp_buffer = NULL;
390    } else
391        av_freep(&rbsp->rbsp_buffer);
392
393    return;
394}
395
396int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
397                          void *logctx, int is_nalff, int nal_length_size,
398                          enum AVCodecID codec_id, int small_padding, int use_ref)
399{
400    GetByteContext bc;
401    int consumed, ret = 0;
402    int next_avc = is_nalff ? 0 : length;
403    int64_t padding = small_padding ? 0 : MAX_MBPAIR_SIZE;
404
405    bytestream2_init(&bc, buf, length);
406    alloc_rbsp_buffer(&pkt->rbsp, length + padding, use_ref);
407
408    if (!pkt->rbsp.rbsp_buffer)
409        return AVERROR(ENOMEM);
410
411    pkt->rbsp.rbsp_buffer_size = 0;
412    pkt->nb_nals = 0;
413    while (bytestream2_get_bytes_left(&bc) >= 4) {
414        H2645NAL *nal;
415        int extract_length = 0;
416        int skip_trailing_zeros = 1;
417
418        if (bytestream2_tell(&bc) == next_avc) {
419            int i = 0;
420            extract_length = get_nalsize(nal_length_size,
421                                         bc.buffer, bytestream2_get_bytes_left(&bc), &i, logctx);
422            if (extract_length < 0)
423                return extract_length;
424
425            bytestream2_skip(&bc, nal_length_size);
426
427            next_avc = bytestream2_tell(&bc) + extract_length;
428        } else {
429            int buf_index;
430
431            if (bytestream2_tell(&bc) > next_avc)
432                av_log(logctx, AV_LOG_WARNING, "Exceeded next NALFF position, re-syncing.\n");
433
434            /* search start code */
435            buf_index = find_next_start_code(bc.buffer, buf + next_avc);
436
437            bytestream2_skip(&bc, buf_index);
438
439            if (!bytestream2_get_bytes_left(&bc)) {
440                if (pkt->nb_nals > 0) {
441                    // No more start codes: we discarded some irrelevant
442                    // bytes at the end of the packet.
443                    return 0;
444                } else {
445                    av_log(logctx, AV_LOG_ERROR, "No start code is found.\n");
446                    return AVERROR_INVALIDDATA;
447                }
448            }
449
450            extract_length = FFMIN(bytestream2_get_bytes_left(&bc), next_avc - bytestream2_tell(&bc));
451
452            if (bytestream2_tell(&bc) >= next_avc) {
453                /* skip to the start of the next NAL */
454                bytestream2_skip(&bc, next_avc - bytestream2_tell(&bc));
455                continue;
456            }
457        }
458
459        if (pkt->nals_allocated < pkt->nb_nals + 1) {
460            int new_size = pkt->nals_allocated + 1;
461            void *tmp;
462
463            if (new_size >= INT_MAX / sizeof(*pkt->nals))
464                return AVERROR(ENOMEM);
465
466            tmp = av_fast_realloc(pkt->nals, &pkt->nal_buffer_size, new_size * sizeof(*pkt->nals));
467            if (!tmp)
468                return AVERROR(ENOMEM);
469
470            pkt->nals = tmp;
471            memset(pkt->nals + pkt->nals_allocated, 0, sizeof(*pkt->nals));
472
473            nal = &pkt->nals[pkt->nb_nals];
474            nal->skipped_bytes_pos_size = FFMIN(1024, extract_length/3+1); // initial buffer size
475            nal->skipped_bytes_pos = av_malloc_array(nal->skipped_bytes_pos_size, sizeof(*nal->skipped_bytes_pos));
476            if (!nal->skipped_bytes_pos)
477                return AVERROR(ENOMEM);
478
479            pkt->nals_allocated = new_size;
480        }
481        nal = &pkt->nals[pkt->nb_nals];
482
483        consumed = ff_h2645_extract_rbsp(bc.buffer, extract_length, &pkt->rbsp, nal, small_padding);
484        if (consumed < 0)
485            return consumed;
486
487        if (is_nalff && (extract_length != consumed) && extract_length)
488            av_log(logctx, AV_LOG_DEBUG,
489                   "NALFF: Consumed only %d bytes instead of %d\n",
490                   consumed, extract_length);
491
492        bytestream2_skip(&bc, consumed);
493
494        /* see commit 3566042a0 */
495        if (bytestream2_get_bytes_left(&bc) >= 4 &&
496            bytestream2_peek_be32(&bc) == 0x000001E0)
497            skip_trailing_zeros = 0;
498
499        nal->size_bits = get_bit_length(nal, 1 + (codec_id == AV_CODEC_ID_HEVC),
500                                        skip_trailing_zeros);
501
502        if (nal->size <= 0 || nal->size_bits <= 0)
503            continue;
504
505        ret = init_get_bits(&nal->gb, nal->data, nal->size_bits);
506        if (ret < 0)
507            return ret;
508
509        /* Reset type in case it contains a stale value from a previously parsed NAL */
510        nal->type = 0;
511
512        if (codec_id == AV_CODEC_ID_HEVC)
513            ret = hevc_parse_nal_header(nal, logctx);
514        else
515            ret = h264_parse_nal_header(nal, logctx);
516        if (ret < 0) {
517            av_log(logctx, AV_LOG_WARNING, "Invalid NAL unit %d, skipping.\n",
518                   nal->type);
519            continue;
520        }
521
522        pkt->nb_nals++;
523    }
524
525    return 0;
526}
527
528void ff_h2645_packet_uninit(H2645Packet *pkt)
529{
530    int i;
531    for (i = 0; i < pkt->nals_allocated; i++) {
532        av_freep(&pkt->nals[i].skipped_bytes_pos);
533    }
534    av_freep(&pkt->nals);
535    pkt->nals_allocated = pkt->nal_buffer_size = 0;
536    if (pkt->rbsp.rbsp_buffer_ref) {
537        av_buffer_unref(&pkt->rbsp.rbsp_buffer_ref);
538        pkt->rbsp.rbsp_buffer = NULL;
539    } else
540        av_freep(&pkt->rbsp.rbsp_buffer);
541    pkt->rbsp.rbsp_buffer_alloc_size = pkt->rbsp.rbsp_buffer_size = 0;
542}
543