FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/h264_mp4toannexb_bsf.c
Date: 2021-09-26 18:22:30
Exec Total Coverage
Lines: 115 150 76.7%
Branches: 71 114 62.3%

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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
28 #include "bsf.h"
29 #include "bsf_internal.h"
30 #include "bytestream.h"
31 #include "defs.h"
32 #include "h264.h"
33
34 typedef struct H264BSFContext {
35 uint8_t *sps;
36 uint8_t *pps;
37 int sps_size;
38 int pps_size;
39 uint8_t length_size;
40 uint8_t new_idr;
41 uint8_t idr_sps_seen;
42 uint8_t idr_pps_seen;
43 int extradata_parsed;
44 } H264BSFContext;
45
46 3504 static void count_or_copy(uint8_t **out, uint64_t *out_size,
47 const uint8_t *in, int in_size, int ps, int copy)
48 {
49
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3504 uint8_t start_code_size = ps < 0 ? 0 : *out_size == 0 || ps ? 4 : 3;
50
51
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3504 if (copy) {
52 1750 memcpy(*out + start_code_size, in, in_size);
53
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1750 if (start_code_size == 4) {
54 397 AV_WB32(*out, 1);
55
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1353 } else if (start_code_size) {
56 1339 (*out)[0] =
57 1339 (*out)[1] = 0;
58 1339 (*out)[2] = 1;
59 }
60 1750 *out += start_code_size + in_size;
61 }
62 3504 *out_size += start_code_size + in_size;
63 3504 }
64
65 5 static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
66 {
67 5 H264BSFContext *s = ctx->priv_data;
68 5 GetByteContext ogb, *gb = &ogb;
69 uint16_t unit_size;
70 5 uint32_t total_size = 0;
71 5 uint8_t *out = NULL, unit_nb, sps_done = 0;
72 static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
73 5 int length_size, pps_offset = 0;
74
75 5 bytestream2_init(gb, ctx->par_in->extradata, ctx->par_in->extradata_size);
76
77 5 bytestream2_skipu(gb, 4);
78
79 /* retrieve length coded size */
80 5 length_size = (bytestream2_get_byteu(gb) & 0x3) + 1;
81
82 /* retrieve sps and pps unit(s) */
83 5 unit_nb = bytestream2_get_byteu(gb) & 0x1f; /* number of sps unit(s) */
84
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5 if (!unit_nb) {
85 goto pps;
86 }
87
88
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15 while (unit_nb--) {
89 int err;
90
91 /* possible overread ok due to padding */
92 10 unit_size = bytestream2_get_be16u(gb);
93 10 total_size += unit_size + 4;
94 av_assert1(total_size <= INT_MAX - padding);
95
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10 if (bytestream2_get_bytes_left(gb) < unit_size + !sps_done) {
96 av_log(ctx, AV_LOG_ERROR, "Global extradata truncated, "
97 "corrupted stream or invalid MP4/AVCC bitstream\n");
98 av_free(out);
99 return AVERROR_INVALIDDATA;
100 }
101
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10 if ((err = av_reallocp(&out, total_size + padding)) < 0)
102 return err;
103 10 memcpy(out + total_size - unit_size - 4, nalu_header, 4);
104 10 bytestream2_get_bufferu(gb, out + total_size - unit_size, unit_size);
105 10 pps:
106
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10 if (!unit_nb && !sps_done++) {
107 5 unit_nb = bytestream2_get_byteu(gb); /* number of pps unit(s) */
108 5 pps_offset = total_size;
109 }
110 }
111
112
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5 if (out)
113 5 memset(out + total_size, 0, padding);
114
115
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5 if (pps_offset) {
116 5 s->sps = out;
117 5 s->sps_size = pps_offset;
118 } else {
119 av_log(ctx, AV_LOG_WARNING,
120 "Warning: SPS NALU missing or invalid. "
121 "The resulting stream may not play.\n");
122 }
123
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5 if (pps_offset < total_size) {
124 5 s->pps = out + pps_offset;
125 5 s->pps_size = total_size - pps_offset;
126 } else {
127 av_log(ctx, AV_LOG_WARNING,
128 "Warning: PPS NALU missing or invalid. "
129 "The resulting stream may not play.\n");
130 }
131
132 5 av_freep(&ctx->par_out->extradata);
133 5 ctx->par_out->extradata = out;
134 5 ctx->par_out->extradata_size = total_size;
135
136 5 return length_size;
137 }
138
139 5 static int h264_mp4toannexb_init(AVBSFContext *ctx)
140 {
141 5 H264BSFContext *s = ctx->priv_data;
142 5 int extra_size = ctx->par_in->extradata_size;
143 int ret;
144
145 /* retrieve sps and pps NAL units from extradata */
146
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5 if (!extra_size ||
147
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5 (extra_size >= 3 && AV_RB24(ctx->par_in->extradata) == 1) ||
148
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5 (extra_size >= 4 && AV_RB32(ctx->par_in->extradata) == 1)) {
149 av_log(ctx, AV_LOG_VERBOSE,
150 "The input looks like it is Annex B already\n");
151
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5 } else if (extra_size >= 7) {
152 5 ret = h264_extradata_to_annexb(ctx, AV_INPUT_BUFFER_PADDING_SIZE);
153
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5 if (ret < 0)
154 return ret;
155
156 5 s->length_size = ret;
157 5 s->new_idr = 1;
158 5 s->idr_sps_seen = 0;
159 5 s->idr_pps_seen = 0;
160 5 s->extradata_parsed = 1;
161 } else {
162 av_log(ctx, AV_LOG_ERROR, "Invalid extradata size: %d\n", extra_size);
163 return AVERROR_INVALIDDATA;
164 }
165
166 5 return 0;
167 }
168
169 798 static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *opkt)
170 {
171 798 H264BSFContext *s = ctx->priv_data;
172 AVPacket *in;
173 uint8_t unit_type, new_idr, sps_seen, pps_seen;
174 const uint8_t *buf;
175 const uint8_t *buf_end;
176 uint8_t *out;
177 uint64_t out_size;
178 int ret;
179
180 798 ret = ff_bsf_get_packet(ctx, &in);
181
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798 if (ret < 0)
182 400 return ret;
183
184 /* nothing to filter */
185
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398 if (!s->extradata_parsed) {
186 av_packet_move_ref(opkt, in);
187 av_packet_free(&in);
188 return 0;
189 }
190
191 398 buf_end = in->data + in->size;
192
193 #define LOG_ONCE(...) \
194 if (j) \
195 av_log(__VA_ARGS__)
196
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1192 for (int j = 0; j < 2; j++) {
197 795 buf = in->data;
198 795 new_idr = s->new_idr;
199 795 sps_seen = s->idr_sps_seen;
200 795 pps_seen = s->idr_pps_seen;
201 795 out_size = 0;
202
203 do {
204 3477 uint32_t nal_size = 0;
205
206 /* possible overread ok due to padding */
207
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17385 for (int i = 0; i < s->length_size; i++)
208 13908 nal_size = (nal_size << 8) | buf[i];
209
210 3477 buf += s->length_size;
211
212 /* This check requires the cast as the right side might
213 * otherwise be promoted to an unsigned value. */
214
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3477 if ((int64_t)nal_size > buf_end - buf) {
215 1 ret = AVERROR_INVALIDDATA;
216 1 goto fail;
217 }
218
219
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3476 if (!nal_size)
220 continue;
221
222 3476 unit_type = *buf & 0x1f;
223
224
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3476 if (unit_type == H264_NAL_SPS) {
225 sps_seen = new_idr = 1;
226
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3476 } else if (unit_type == H264_NAL_PPS) {
227 pps_seen = new_idr = 1;
228 /* if SPS has not been seen yet, prepend the AVCC one to PPS */
229 if (!sps_seen) {
230 if (!s->sps_size) {
231 LOG_ONCE(ctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n");
232 } else {
233 count_or_copy(&out, &out_size, s->sps, s->sps_size, -1, j);
234 sps_seen = 1;
235 }
236 }
237 }
238
239 /* If this is a new IDR picture following an IDR picture, reset the idr flag.
240 * Just check first_mb_in_slice to be 0 as this is the simplest solution.
241 * This could be checking idr_pic_id instead, but would complexify the parsing. */
242
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3476 if (!new_idr && unit_type == H264_NAL_IDR_SLICE && (buf[1] & 0x80))
243 new_idr = 1;
244
245 /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */
246
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3476 if (new_idr && unit_type == H264_NAL_IDR_SLICE && !sps_seen && !pps_seen) {
247
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28 if (ctx->par_out->extradata)
248 28 count_or_copy(&out, &out_size, ctx->par_out->extradata,
249 28 ctx->par_out->extradata_size, -1, j);
250 28 new_idr = 0;
251 /* if only SPS has been seen, also insert PPS */
252
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3448 } else if (new_idr && unit_type == H264_NAL_IDR_SLICE && sps_seen && !pps_seen) {
253 if (!s->pps_size) {
254 LOG_ONCE(ctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n");
255 } else {
256 count_or_copy(&out, &out_size, s->pps, s->pps_size, -1, j);
257 }
258 }
259
260
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3476 count_or_copy(&out, &out_size, buf, nal_size,
261 unit_type == H264_NAL_SPS || unit_type == H264_NAL_PPS, j);
262
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3476 if (!new_idr && unit_type == H264_NAL_SLICE) {
263 24 new_idr = 1;
264 24 sps_seen = 0;
265 24 pps_seen = 0;
266 }
267
268 3476 buf += nal_size;
269
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3476 } while (buf < buf_end);
270
271
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794 if (!j) {
272
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397 if (out_size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE) {
273 ret = AVERROR_INVALIDDATA;
274 goto fail;
275 }
276 397 ret = av_new_packet(opkt, out_size);
277
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397 if (ret < 0)
278 goto fail;
279 397 out = opkt->data;
280 }
281 }
282 #undef LOG_ONCE
283
284 av_assert1(out_size == opkt->size);
285
286 397 s->new_idr = new_idr;
287 397 s->idr_sps_seen = sps_seen;
288 397 s->idr_pps_seen = pps_seen;
289
290 397 ret = av_packet_copy_props(opkt, in);
291
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397 if (ret < 0)
292 goto fail;
293
294 397 fail:
295
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398 if (ret < 0)
296 1 av_packet_unref(opkt);
297 398 av_packet_free(&in);
298
299 398 return ret;
300 }
301
302 static void h264_mp4toannexb_flush(AVBSFContext *ctx)
303 {
304 H264BSFContext *s = ctx->priv_data;
305
306 s->idr_sps_seen = 0;
307 s->idr_pps_seen = 0;
308 s->new_idr = s->extradata_parsed;
309 }
310
311 static const enum AVCodecID codec_ids[] = {
312 AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
313 };
314
315 const AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
316 .name = "h264_mp4toannexb",
317 .priv_data_size = sizeof(H264BSFContext),
318 .init = h264_mp4toannexb_init,
319 .filter = h264_mp4toannexb_filter,
320 .flush = h264_mp4toannexb_flush,
321 .codec_ids = codec_ids,
322 };
323