1 /*
2 * H.264 MP4 to Annex B byte stream format filter
3 * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
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 <string.h>
23
24 #include "libavutil/avassert.h"
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/mem.h"
27 #ifdef OHOS_DRM
28 #include "libavutil/encryption_info.h"
29 #endif
30
31 #include "bsf.h"
32 #include "bsf_internal.h"
33 #include "bytestream.h"
34 #include "defs.h"
35 #include "h264.h"
36
37 typedef struct H264BSFContext {
38 uint8_t *sps;
39 uint8_t *pps;
40 int sps_size;
41 int pps_size;
42 uint8_t length_size;
43 uint8_t new_idr;
44 uint8_t idr_sps_seen;
45 uint8_t idr_pps_seen;
46 int extradata_parsed;
47 } H264BSFContext;
48
count_or_copy(uint8_t ** out,uint64_t * out_size,const uint8_t * in,int in_size,int ps,int copy)49 static void count_or_copy(uint8_t **out, uint64_t *out_size,
50 const uint8_t *in, int in_size, int ps, int copy)
51 {
52 #ifdef OHOS_OPT_COMPAT
53 uint8_t start_code_size = ps < 0 ? 0 : 4;
54 #else
55 uint8_t start_code_size = ps < 0 ? 0 : *out_size == 0 || ps ? 4 : 3;
56 #endif
57 if (copy) {
58 memcpy(*out + start_code_size, in, in_size);
59 if (start_code_size == 4) {
60 AV_WB32(*out, 1);
61 } else if (start_code_size) {
62 (*out)[0] =
63 (*out)[1] = 0;
64 (*out)[2] = 1;
65 }
66 *out += start_code_size + in_size;
67 }
68 *out_size += start_code_size + in_size;
69 }
70
h264_extradata_to_annexb(AVBSFContext * ctx,const int padding)71 static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
72 {
73 H264BSFContext *s = ctx->priv_data;
74 GetByteContext ogb, *gb = &ogb;
75 uint16_t unit_size;
76 uint32_t total_size = 0;
77 uint8_t *out = NULL, unit_nb, sps_done = 0;
78 static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
79 int length_size, pps_offset = 0;
80
81 bytestream2_init(gb, ctx->par_in->extradata, ctx->par_in->extradata_size);
82
83 bytestream2_skipu(gb, 4);
84
85 /* retrieve length coded size */
86 length_size = (bytestream2_get_byteu(gb) & 0x3) + 1;
87
88 /* retrieve sps and pps unit(s) */
89 unit_nb = bytestream2_get_byteu(gb) & 0x1f; /* number of sps unit(s) */
90 if (!unit_nb) {
91 goto pps;
92 }
93
94 while (unit_nb--) {
95 int err;
96
97 /* possible overread ok due to padding */
98 unit_size = bytestream2_get_be16u(gb);
99 total_size += unit_size + 4;
100 av_assert1(total_size <= INT_MAX - padding);
101 if (bytestream2_get_bytes_left(gb) < unit_size + !sps_done) {
102 av_log(ctx, AV_LOG_ERROR, "Global extradata truncated, "
103 "corrupted stream or invalid MP4/AVCC bitstream\n");
104 av_free(out);
105 return AVERROR_INVALIDDATA;
106 }
107 if ((err = av_reallocp(&out, total_size + padding)) < 0)
108 return err;
109 memcpy(out + total_size - unit_size - 4, nalu_header, 4);
110 bytestream2_get_bufferu(gb, out + total_size - unit_size, unit_size);
111 pps:
112 if (!unit_nb && !sps_done++) {
113 unit_nb = bytestream2_get_byteu(gb); /* number of pps unit(s) */
114 pps_offset = total_size;
115 }
116 }
117
118 if (out)
119 memset(out + total_size, 0, padding);
120
121 if (pps_offset) {
122 s->sps = out;
123 s->sps_size = pps_offset;
124 } else {
125 av_log(ctx, AV_LOG_WARNING,
126 "Warning: SPS NALU missing or invalid. "
127 "The resulting stream may not play.\n");
128 }
129 if (pps_offset < total_size) {
130 s->pps = out + pps_offset;
131 s->pps_size = total_size - pps_offset;
132 } else {
133 av_log(ctx, AV_LOG_WARNING,
134 "Warning: PPS NALU missing or invalid. "
135 "The resulting stream may not play.\n");
136 }
137
138 av_freep(&ctx->par_out->extradata);
139 ctx->par_out->extradata = out;
140 ctx->par_out->extradata_size = total_size;
141
142 return length_size;
143 }
144
h264_mp4toannexb_init(AVBSFContext * ctx)145 static int h264_mp4toannexb_init(AVBSFContext *ctx)
146 {
147 H264BSFContext *s = ctx->priv_data;
148 int extra_size = ctx->par_in->extradata_size;
149 int ret;
150
151 /* retrieve sps and pps NAL units from extradata */
152 if (!extra_size ||
153 (extra_size >= 3 && AV_RB24(ctx->par_in->extradata) == 1) ||
154 (extra_size >= 4 && AV_RB32(ctx->par_in->extradata) == 1)) {
155 av_log(ctx, AV_LOG_VERBOSE,
156 "The input looks like it is Annex B already\n");
157 } else if (extra_size >= 7) {
158 ret = h264_extradata_to_annexb(ctx, AV_INPUT_BUFFER_PADDING_SIZE);
159 if (ret < 0)
160 return ret;
161
162 s->length_size = ret;
163 s->new_idr = 1;
164 s->idr_sps_seen = 0;
165 s->idr_pps_seen = 0;
166 s->extradata_parsed = 1;
167 } else {
168 av_log(ctx, AV_LOG_ERROR, "Invalid extradata size: %d\n", extra_size);
169 return AVERROR_INVALIDDATA;
170 }
171
172 return 0;
173 }
174
175 #ifdef OHOS_DRM
h264_mp4toannexb_modify_encryption_info(AVPacket * pkt,uint64_t new_data_size,uint64_t old_data_size,int copy)176 static void h264_mp4toannexb_modify_encryption_info(AVPacket *pkt, uint64_t new_data_size, uint64_t old_data_size,
177 int copy)
178 {
179 AV_DrmCencInfo *side_data = NULL;
180 size_t side_data_size = 0;
181 if ((copy == 0) || (new_data_size == old_data_size)) {
182 return;
183 }
184 side_data = (AV_DrmCencInfo *)av_packet_get_side_data(pkt, AV_PKT_DATA_ENCRYPTION_INFO, &side_data_size);
185 if ((side_data != NULL) && (side_data_size != 0) && (side_data->sub_sample_num <= AV_DRM_MAX_SUB_SAMPLE_NUM)) {
186 uint64_t total_size = 0;
187 for (uint32_t i = 0; i < side_data->sub_sample_num; i++) {
188 total_size +=
189 (uint64_t)(side_data->sub_samples[i].clear_header_len + side_data->sub_samples[i].pay_load_len);
190 if (total_size < new_data_size) {
191 continue;
192 }
193 if (new_data_size > old_data_size) {
194 side_data->sub_samples[i].clear_header_len += (uint32_t)(new_data_size - old_data_size);
195 } else {
196 uint32_t diff_size = (uint32_t)(old_data_size - new_data_size);
197 if (side_data->sub_samples[i].clear_header_len < diff_size) {
198 return;
199 }
200 side_data->sub_samples[i].clear_header_len -= diff_size;
201 }
202 break;
203 }
204 }
205 return;
206 }
207 #endif
208
h264_mp4toannexb_filter(AVBSFContext * ctx,AVPacket * opkt)209 static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *opkt)
210 {
211 H264BSFContext *s = ctx->priv_data;
212 AVPacket *in;
213 uint8_t unit_type, new_idr, sps_seen, pps_seen;
214 const uint8_t *buf;
215 const uint8_t *buf_end;
216 uint8_t *out;
217 uint64_t out_size;
218 int ret;
219 #ifdef OHOS_DRM
220 uint64_t old_out_size;
221 #endif
222
223 ret = ff_bsf_get_packet(ctx, &in);
224 if (ret < 0)
225 return ret;
226
227 /* nothing to filter */
228 if (!s->extradata_parsed) {
229 av_packet_move_ref(opkt, in);
230 av_packet_free(&in);
231 return 0;
232 }
233
234 buf_end = in->data + in->size;
235
236 #define LOG_ONCE(...) \
237 if (j) \
238 av_log(__VA_ARGS__)
239 for (int j = 0; j < 2; j++) {
240 buf = in->data;
241 new_idr = s->new_idr;
242 sps_seen = s->idr_sps_seen;
243 pps_seen = s->idr_pps_seen;
244 out_size = 0;
245 #ifdef OHOS_DRM
246 old_out_size = out_size;
247 #endif
248
249 do {
250 uint32_t nal_size = 0;
251
252 /* possible overread ok due to padding */
253 for (int i = 0; i < s->length_size; i++)
254 nal_size = (nal_size << 8) | buf[i];
255
256 buf += s->length_size;
257
258 /* This check requires the cast as the right side might
259 * otherwise be promoted to an unsigned value. */
260 if ((int64_t)nal_size > buf_end - buf) {
261 ret = AVERROR_INVALIDDATA;
262 goto fail;
263 }
264
265 if (!nal_size)
266 continue;
267
268 unit_type = *buf & 0x1f;
269
270 if (unit_type == H264_NAL_SPS) {
271 sps_seen = new_idr = 1;
272 } else if (unit_type == H264_NAL_PPS) {
273 pps_seen = new_idr = 1;
274 /* if SPS has not been seen yet, prepend the AVCC one to PPS */
275 if (!sps_seen) {
276 if (!s->sps_size) {
277 LOG_ONCE(ctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n");
278 } else {
279 count_or_copy(&out, &out_size, s->sps, s->sps_size, -1, j);
280 #ifdef OHOS_DRM
281 h264_mp4toannexb_modify_encryption_info(in, out_size, old_out_size, j);
282 old_out_size = out_size;
283 #endif
284 sps_seen = 1;
285 }
286 }
287 }
288
289 /* If this is a new IDR picture following an IDR picture, reset the idr flag.
290 * Just check first_mb_in_slice to be 0 as this is the simplest solution.
291 * This could be checking idr_pic_id instead, but would complexify the parsing. */
292 if (!new_idr && unit_type == H264_NAL_IDR_SLICE && (buf[1] & 0x80))
293 new_idr = 1;
294
295 /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */
296 if (new_idr && unit_type == H264_NAL_IDR_SLICE && !sps_seen && !pps_seen) {
297 if (ctx->par_out->extradata)
298 count_or_copy(&out, &out_size, ctx->par_out->extradata,
299 ctx->par_out->extradata_size, -1, j);
300 #ifdef OHOS_DRM
301 h264_mp4toannexb_modify_encryption_info(in, out_size, old_out_size, j);
302 old_out_size = out_size;
303 #endif
304 new_idr = 0;
305 /* if only SPS has been seen, also insert PPS */
306 } else if (new_idr && unit_type == H264_NAL_IDR_SLICE && sps_seen && !pps_seen) {
307 if (!s->pps_size) {
308 LOG_ONCE(ctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n");
309 } else {
310 count_or_copy(&out, &out_size, s->pps, s->pps_size, -1, j);
311 #ifdef OHOS_DRM
312 h264_mp4toannexb_modify_encryption_info(in, out_size, old_out_size, j);
313 old_out_size = out_size;
314 #endif
315 }
316 }
317
318 count_or_copy(&out, &out_size, buf, nal_size,
319 unit_type == H264_NAL_SPS || unit_type == H264_NAL_PPS, j);
320 #ifdef OHOS_DRM
321 h264_mp4toannexb_modify_encryption_info(in, out_size,
322 (uint64_t)(nal_size + old_out_size + s->length_size), j);
323 old_out_size = out_size;
324 #endif
325 if (!new_idr && unit_type == H264_NAL_SLICE) {
326 new_idr = 1;
327 sps_seen = 0;
328 pps_seen = 0;
329 }
330
331 buf += nal_size;
332 } while (buf < buf_end);
333
334 if (!j) {
335 if (out_size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE) {
336 ret = AVERROR_INVALIDDATA;
337 goto fail;
338 }
339 ret = av_new_packet(opkt, out_size);
340 if (ret < 0)
341 goto fail;
342 out = opkt->data;
343 }
344 }
345 #undef LOG_ONCE
346
347 av_assert1(out_size == opkt->size);
348
349 s->new_idr = new_idr;
350 s->idr_sps_seen = sps_seen;
351 s->idr_pps_seen = pps_seen;
352
353 ret = av_packet_copy_props(opkt, in);
354 if (ret < 0)
355 goto fail;
356
357 fail:
358 if (ret < 0)
359 av_packet_unref(opkt);
360 av_packet_free(&in);
361
362 return ret;
363 }
364
h264_mp4toannexb_flush(AVBSFContext * ctx)365 static void h264_mp4toannexb_flush(AVBSFContext *ctx)
366 {
367 H264BSFContext *s = ctx->priv_data;
368
369 s->idr_sps_seen = 0;
370 s->idr_pps_seen = 0;
371 s->new_idr = s->extradata_parsed;
372 }
373
374 static const enum AVCodecID codec_ids[] = {
375 AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
376 };
377
378 const FFBitStreamFilter ff_h264_mp4toannexb_bsf = {
379 .p.name = "h264_mp4toannexb",
380 .p.codec_ids = codec_ids,
381 .priv_data_size = sizeof(H264BSFContext),
382 .init = h264_mp4toannexb_init,
383 .filter = h264_mp4toannexb_filter,
384 .flush = h264_mp4toannexb_flush,
385 };
386