1 /*
2 * AVC helper functions for muxers
3 * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
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 #include "libavutil/intreadwrite.h"
23 #include "libavcodec/h264.h"
24 #include "libavcodec/get_bits.h"
25 #include "avformat.h"
26 #include "avio.h"
27 #include "avc.h"
28 #include "avio_internal.h"
29
avc_find_startcode_internal(const uint8_t * p,const uint8_t * end)30 static const uint8_t *avc_find_startcode_internal(const uint8_t *p, const uint8_t *end)
31 {
32 const uint8_t *a = p + 4 - ((intptr_t)p & 3);
33
34 for (end -= 3; p < a && p < end; p++) {
35 if (p[0] == 0 && p[1] == 0 && p[2] == 1)
36 return p;
37 }
38
39 for (end -= 3; p < end; p += 4) {
40 uint32_t x = *(const uint32_t*)p;
41 // if ((x - 0x01000100) & (~x) & 0x80008000) // little endian
42 // if ((x - 0x00010001) & (~x) & 0x00800080) // big endian
43 if ((x - 0x01010101) & (~x) & 0x80808080) { // generic
44 if (p[1] == 0) {
45 if (p[0] == 0 && p[2] == 1)
46 return p;
47 if (p[2] == 0 && p[3] == 1)
48 return p+1;
49 }
50 if (p[3] == 0) {
51 if (p[2] == 0 && p[4] == 1)
52 return p+2;
53 if (p[4] == 0 && p[5] == 1)
54 return p+3;
55 }
56 }
57 }
58
59 for (end += 3; p < end; p++) {
60 if (p[0] == 0 && p[1] == 0 && p[2] == 1)
61 return p;
62 }
63
64 return end + 3;
65 }
66
ff_avc_find_startcode(const uint8_t * p,const uint8_t * end)67 const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){
68 const uint8_t *out = avc_find_startcode_internal(p, end);
69 if(p<out && out<end && !out[-1]) out--;
70 return out;
71 }
72
avc_parse_nal_units(AVIOContext * pb,NALUList * list,const uint8_t * buf_in,int size)73 static int avc_parse_nal_units(AVIOContext *pb, NALUList *list,
74 const uint8_t *buf_in, int size)
75 {
76 const uint8_t *p = buf_in;
77 const uint8_t *end = p + size;
78 const uint8_t *nal_start, *nal_end;
79
80 size = 0;
81 nal_start = ff_avc_find_startcode(p, end);
82 for (;;) {
83 const size_t nalu_limit = SIZE_MAX / sizeof(*list->nalus);
84 while (nal_start < end && !*(nal_start++));
85 if (nal_start == end)
86 break;
87
88 nal_end = ff_avc_find_startcode(nal_start, end);
89 if (pb) {
90 avio_wb32(pb, nal_end - nal_start);
91 avio_write(pb, nal_start, nal_end - nal_start);
92 } else if (list->nb_nalus >= nalu_limit) {
93 return AVERROR(ERANGE);
94 } else {
95 NALU *tmp = av_fast_realloc(list->nalus, &list->nalus_array_size,
96 (list->nb_nalus + 1) * sizeof(*list->nalus));
97 if (!tmp)
98 return AVERROR(ENOMEM);
99 list->nalus = tmp;
100 tmp[list->nb_nalus++] = (NALU){ .offset = nal_start - p,
101 .size = nal_end - nal_start };
102 }
103 size += 4 + nal_end - nal_start;
104 nal_start = nal_end;
105 }
106 return size;
107 }
108
ff_avc_parse_nal_units(AVIOContext * pb,const uint8_t * buf_in,int size)109 int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size)
110 {
111 return avc_parse_nal_units(pb, NULL, buf_in, size);
112 }
113
ff_nal_units_create_list(NALUList * list,const uint8_t * buf,int size)114 int ff_nal_units_create_list(NALUList *list, const uint8_t *buf, int size)
115 {
116 list->nb_nalus = 0;
117 return avc_parse_nal_units(NULL, list, buf, size);
118 }
119
ff_nal_units_write_list(const NALUList * list,AVIOContext * pb,const uint8_t * buf)120 void ff_nal_units_write_list(const NALUList *list, AVIOContext *pb,
121 const uint8_t *buf)
122 {
123 for (unsigned i = 0; i < list->nb_nalus; i++) {
124 avio_wb32(pb, list->nalus[i].size);
125 avio_write(pb, buf + list->nalus[i].offset, list->nalus[i].size);
126 }
127 }
128
ff_avc_parse_nal_units_buf(const uint8_t * buf_in,uint8_t ** buf,int * size)129 int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size)
130 {
131 AVIOContext *pb;
132 int ret = avio_open_dyn_buf(&pb);
133 if(ret < 0)
134 return ret;
135
136 ff_avc_parse_nal_units(pb, buf_in, *size);
137
138 *size = avio_close_dyn_buf(pb, buf);
139 return 0;
140 }
141
ff_isom_write_avcc(AVIOContext * pb,const uint8_t * data,int len)142 int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len)
143 {
144 AVIOContext *sps_pb = NULL, *pps_pb = NULL, *sps_ext_pb = NULL;
145 uint8_t *buf, *end, *start;
146 uint8_t *sps, *pps, *sps_ext;
147 uint32_t sps_size = 0, pps_size = 0, sps_ext_size = 0;
148 int ret, nb_sps = 0, nb_pps = 0, nb_sps_ext = 0;
149
150 if (len <= 6)
151 return AVERROR_INVALIDDATA;
152
153 /* check for H.264 start code */
154 if (AV_RB32(data) != 0x00000001 &&
155 AV_RB24(data) != 0x000001) {
156 avio_write(pb, data, len);
157 return 0;
158 }
159
160 ret = ff_avc_parse_nal_units_buf(data, &buf, &len);
161 if (ret < 0)
162 return ret;
163 start = buf;
164 end = buf + len;
165
166 ret = avio_open_dyn_buf(&sps_pb);
167 if (ret < 0)
168 goto fail;
169 ret = avio_open_dyn_buf(&pps_pb);
170 if (ret < 0)
171 goto fail;
172 ret = avio_open_dyn_buf(&sps_ext_pb);
173 if (ret < 0)
174 goto fail;
175
176 /* look for sps and pps */
177 while (end - buf > 4) {
178 uint32_t size;
179 uint8_t nal_type;
180 size = FFMIN(AV_RB32(buf), end - buf - 4);
181 buf += 4;
182 nal_type = buf[0] & 0x1f;
183
184 if (nal_type == 7) { /* SPS */
185 nb_sps++;
186 if (size > UINT16_MAX || nb_sps >= H264_MAX_SPS_COUNT) {
187 ret = AVERROR_INVALIDDATA;
188 goto fail;
189 }
190 avio_wb16(sps_pb, size);
191 avio_write(sps_pb, buf, size);
192 } else if (nal_type == 8) { /* PPS */
193 nb_pps++;
194 if (size > UINT16_MAX || nb_pps >= H264_MAX_PPS_COUNT) {
195 ret = AVERROR_INVALIDDATA;
196 goto fail;
197 }
198 avio_wb16(pps_pb, size);
199 avio_write(pps_pb, buf, size);
200 } else if (nal_type == 13) { /* SPS_EXT */
201 nb_sps_ext++;
202 if (size > UINT16_MAX || nb_sps_ext >= 256) {
203 ret = AVERROR_INVALIDDATA;
204 goto fail;
205 }
206 avio_wb16(sps_ext_pb, size);
207 avio_write(sps_ext_pb, buf, size);
208 }
209
210 buf += size;
211 }
212 sps_size = avio_get_dyn_buf(sps_pb, &sps);
213 pps_size = avio_get_dyn_buf(pps_pb, &pps);
214 sps_ext_size = avio_get_dyn_buf(sps_ext_pb, &sps_ext);
215
216 if (sps_size < 6 || !pps_size) {
217 ret = AVERROR_INVALIDDATA;
218 goto fail;
219 }
220
221 avio_w8(pb, 1); /* version */
222 avio_w8(pb, sps[3]); /* profile */
223 avio_w8(pb, sps[4]); /* profile compat */
224 avio_w8(pb, sps[5]); /* level */
225 avio_w8(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */
226 avio_w8(pb, 0xe0 | nb_sps); /* 3 bits reserved (111) + 5 bits number of sps */
227
228 avio_write(pb, sps, sps_size);
229 avio_w8(pb, nb_pps); /* number of pps */
230 avio_write(pb, pps, pps_size);
231
232 if (sps[3] != 66 && sps[3] != 77 && sps[3] != 88) {
233 H264SPS seq;
234 ret = ff_avc_decode_sps(&seq, sps + 3, sps_size - 3);
235 if (ret < 0)
236 goto fail;
237
238 avio_w8(pb, 0xfc | seq.chroma_format_idc); /* 6 bits reserved (111111) + chroma_format_idc */
239 avio_w8(pb, 0xf8 | (seq.bit_depth_luma - 8)); /* 5 bits reserved (11111) + bit_depth_luma_minus8 */
240 avio_w8(pb, 0xf8 | (seq.bit_depth_chroma - 8)); /* 5 bits reserved (11111) + bit_depth_chroma_minus8 */
241 avio_w8(pb, nb_sps_ext); /* number of sps ext */
242 if (nb_sps_ext)
243 avio_write(pb, sps_ext, sps_ext_size);
244 }
245
246 fail:
247 ffio_free_dyn_buf(&sps_pb);
248 ffio_free_dyn_buf(&pps_pb);
249 ffio_free_dyn_buf(&sps_ext_pb);
250 av_free(start);
251
252 return ret;
253 }
254
ff_avc_write_annexb_extradata(const uint8_t * in,uint8_t ** buf,int * size)255 int ff_avc_write_annexb_extradata(const uint8_t *in, uint8_t **buf, int *size)
256 {
257 uint16_t sps_size, pps_size;
258 uint8_t *out;
259 int out_size;
260
261 *buf = NULL;
262 if (*size >= 4 && (AV_RB32(in) == 0x00000001 || AV_RB24(in) == 0x000001))
263 return 0;
264 if (*size < 11 || in[0] != 1)
265 return AVERROR_INVALIDDATA;
266
267 sps_size = AV_RB16(&in[6]);
268 if (11 + sps_size > *size)
269 return AVERROR_INVALIDDATA;
270 pps_size = AV_RB16(&in[9 + sps_size]);
271 if (11 + sps_size + pps_size > *size)
272 return AVERROR_INVALIDDATA;
273 out_size = 8 + sps_size + pps_size;
274 out = av_mallocz(out_size + AV_INPUT_BUFFER_PADDING_SIZE);
275 if (!out)
276 return AVERROR(ENOMEM);
277 AV_WB32(&out[0], 0x00000001);
278 memcpy(out + 4, &in[8], sps_size);
279 AV_WB32(&out[4 + sps_size], 0x00000001);
280 memcpy(out + 8 + sps_size, &in[11 + sps_size], pps_size);
281 *buf = out;
282 *size = out_size;
283 return 0;
284 }
285
ff_avc_mp4_find_startcode(const uint8_t * start,const uint8_t * end,int nal_length_size)286 const uint8_t *ff_avc_mp4_find_startcode(const uint8_t *start,
287 const uint8_t *end,
288 int nal_length_size)
289 {
290 unsigned int res = 0;
291
292 if (end - start < nal_length_size)
293 return NULL;
294 while (nal_length_size--)
295 res = (res << 8) | *start++;
296
297 if (res > end - start)
298 return NULL;
299
300 return start + res;
301 }
302
ff_nal_unit_extract_rbsp(const uint8_t * src,uint32_t src_len,uint32_t * dst_len,int header_len)303 uint8_t *ff_nal_unit_extract_rbsp(const uint8_t *src, uint32_t src_len,
304 uint32_t *dst_len, int header_len)
305 {
306 uint8_t *dst;
307 uint32_t i, len;
308
309 dst = av_malloc(src_len + AV_INPUT_BUFFER_PADDING_SIZE);
310 if (!dst)
311 return NULL;
312
313 /* NAL unit header */
314 i = len = 0;
315 while (i < header_len && i < src_len)
316 dst[len++] = src[i++];
317
318 while (i + 2 < src_len)
319 if (!src[i] && !src[i + 1] && src[i + 2] == 3) {
320 dst[len++] = src[i++];
321 dst[len++] = src[i++];
322 i++; // remove emulation_prevention_three_byte
323 } else
324 dst[len++] = src[i++];
325
326 while (i < src_len)
327 dst[len++] = src[i++];
328
329 memset(dst + len, 0, AV_INPUT_BUFFER_PADDING_SIZE);
330
331 *dst_len = len;
332 return dst;
333 }
334
335 static const AVRational avc_sample_aspect_ratio[17] = {
336 { 0, 1 },
337 { 1, 1 },
338 { 12, 11 },
339 { 10, 11 },
340 { 16, 11 },
341 { 40, 33 },
342 { 24, 11 },
343 { 20, 11 },
344 { 32, 11 },
345 { 80, 33 },
346 { 18, 11 },
347 { 15, 11 },
348 { 64, 33 },
349 { 160, 99 },
350 { 4, 3 },
351 { 3, 2 },
352 { 2, 1 },
353 };
354
get_ue_golomb(GetBitContext * gb)355 static inline int get_ue_golomb(GetBitContext *gb) {
356 int i;
357 for (i = 0; i < 32 && !get_bits1(gb); i++)
358 ;
359 return get_bitsz(gb, i) + (1 << i) - 1;
360 }
361
get_se_golomb(GetBitContext * gb)362 static inline int get_se_golomb(GetBitContext *gb) {
363 int v = get_ue_golomb(gb) + 1;
364 int sign = -(v & 1);
365 return ((v >> 1) ^ sign) - sign;
366 }
367
ff_avc_decode_sps(H264SPS * sps,const uint8_t * buf,int buf_size)368 int ff_avc_decode_sps(H264SPS *sps, const uint8_t *buf, int buf_size)
369 {
370 int i, j, ret, rbsp_size, aspect_ratio_idc, pic_order_cnt_type;
371 int num_ref_frames_in_pic_order_cnt_cycle;
372 int delta_scale, lastScale = 8, nextScale = 8;
373 int sizeOfScalingList;
374 GetBitContext gb;
375 uint8_t *rbsp_buf;
376
377 rbsp_buf = ff_nal_unit_extract_rbsp(buf, buf_size, &rbsp_size, 0);
378 if (!rbsp_buf)
379 return AVERROR(ENOMEM);
380
381 ret = init_get_bits8(&gb, rbsp_buf, rbsp_size);
382 if (ret < 0)
383 goto end;
384
385 memset(sps, 0, sizeof(*sps));
386
387 sps->profile_idc = get_bits(&gb, 8);
388 sps->constraint_set_flags |= get_bits1(&gb) << 0; // constraint_set0_flag
389 sps->constraint_set_flags |= get_bits1(&gb) << 1; // constraint_set1_flag
390 sps->constraint_set_flags |= get_bits1(&gb) << 2; // constraint_set2_flag
391 sps->constraint_set_flags |= get_bits1(&gb) << 3; // constraint_set3_flag
392 sps->constraint_set_flags |= get_bits1(&gb) << 4; // constraint_set4_flag
393 sps->constraint_set_flags |= get_bits1(&gb) << 5; // constraint_set5_flag
394 skip_bits(&gb, 2); // reserved_zero_2bits
395 sps->level_idc = get_bits(&gb, 8);
396 sps->id = get_ue_golomb(&gb);
397
398 if (sps->profile_idc == 100 || sps->profile_idc == 110 ||
399 sps->profile_idc == 122 || sps->profile_idc == 244 || sps->profile_idc == 44 ||
400 sps->profile_idc == 83 || sps->profile_idc == 86 || sps->profile_idc == 118 ||
401 sps->profile_idc == 128 || sps->profile_idc == 138 || sps->profile_idc == 139 ||
402 sps->profile_idc == 134) {
403 sps->chroma_format_idc = get_ue_golomb(&gb); // chroma_format_idc
404 if (sps->chroma_format_idc == 3) {
405 skip_bits1(&gb); // separate_colour_plane_flag
406 }
407 sps->bit_depth_luma = get_ue_golomb(&gb) + 8;
408 sps->bit_depth_chroma = get_ue_golomb(&gb) + 8;
409 skip_bits1(&gb); // qpprime_y_zero_transform_bypass_flag
410 if (get_bits1(&gb)) { // seq_scaling_matrix_present_flag
411 for (i = 0; i < ((sps->chroma_format_idc != 3) ? 8 : 12); i++) {
412 if (!get_bits1(&gb)) // seq_scaling_list_present_flag
413 continue;
414 lastScale = 8;
415 nextScale = 8;
416 sizeOfScalingList = i < 6 ? 16 : 64;
417 for (j = 0; j < sizeOfScalingList; j++) {
418 if (nextScale != 0) {
419 delta_scale = get_se_golomb(&gb);
420 nextScale = (lastScale + delta_scale) & 0xff;
421 }
422 lastScale = nextScale == 0 ? lastScale : nextScale;
423 }
424 }
425 }
426 } else {
427 sps->chroma_format_idc = 1;
428 sps->bit_depth_luma = 8;
429 sps->bit_depth_chroma = 8;
430 }
431
432 get_ue_golomb(&gb); // log2_max_frame_num_minus4
433 pic_order_cnt_type = get_ue_golomb(&gb);
434
435 if (pic_order_cnt_type == 0) {
436 get_ue_golomb(&gb); // log2_max_pic_order_cnt_lsb_minus4
437 } else if (pic_order_cnt_type == 1) {
438 skip_bits1(&gb); // delta_pic_order_always_zero
439 get_se_golomb(&gb); // offset_for_non_ref_pic
440 get_se_golomb(&gb); // offset_for_top_to_bottom_field
441 num_ref_frames_in_pic_order_cnt_cycle = get_ue_golomb(&gb);
442 for (i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; i++)
443 get_se_golomb(&gb); // offset_for_ref_frame
444 }
445
446 get_ue_golomb(&gb); // max_num_ref_frames
447 skip_bits1(&gb); // gaps_in_frame_num_value_allowed_flag
448 get_ue_golomb(&gb); // pic_width_in_mbs_minus1
449 get_ue_golomb(&gb); // pic_height_in_map_units_minus1
450
451 sps->frame_mbs_only_flag = get_bits1(&gb);
452 if (!sps->frame_mbs_only_flag)
453 skip_bits1(&gb); // mb_adaptive_frame_field_flag
454
455 skip_bits1(&gb); // direct_8x8_inference_flag
456
457 if (get_bits1(&gb)) { // frame_cropping_flag
458 get_ue_golomb(&gb); // frame_crop_left_offset
459 get_ue_golomb(&gb); // frame_crop_right_offset
460 get_ue_golomb(&gb); // frame_crop_top_offset
461 get_ue_golomb(&gb); // frame_crop_bottom_offset
462 }
463
464 if (get_bits1(&gb)) { // vui_parameters_present_flag
465 if (get_bits1(&gb)) { // aspect_ratio_info_present_flag
466 aspect_ratio_idc = get_bits(&gb, 8);
467 if (aspect_ratio_idc == 0xff) {
468 sps->sar.num = get_bits(&gb, 16);
469 sps->sar.den = get_bits(&gb, 16);
470 } else if (aspect_ratio_idc < FF_ARRAY_ELEMS(avc_sample_aspect_ratio)) {
471 sps->sar = avc_sample_aspect_ratio[aspect_ratio_idc];
472 }
473 }
474 }
475
476 if (!sps->sar.den) {
477 sps->sar.num = 1;
478 sps->sar.den = 1;
479 }
480
481 ret = 0;
482 end:
483 av_free(rbsp_buf);
484 return ret;
485 }
486