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2ba45a60 DM |
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/intreadwrite.h" | |
25 | #include "libavutil/mem.h" | |
26 | #include "avcodec.h" | |
27 | ||
28 | typedef struct H264BSFContext { | |
f6fa7814 DM |
29 | int32_t sps_offset; |
30 | int32_t pps_offset; | |
2ba45a60 DM |
31 | uint8_t length_size; |
32 | uint8_t new_idr; | |
f6fa7814 DM |
33 | uint8_t idr_sps_seen; |
34 | uint8_t idr_pps_seen; | |
2ba45a60 DM |
35 | int extradata_parsed; |
36 | } H264BSFContext; | |
37 | ||
38 | static int alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size, | |
39 | const uint8_t *sps_pps, uint32_t sps_pps_size, | |
40 | const uint8_t *in, uint32_t in_size) | |
41 | { | |
42 | uint32_t offset = *poutbuf_size; | |
43 | uint8_t nal_header_size = offset ? 3 : 4; | |
44 | int err; | |
45 | ||
46 | *poutbuf_size += sps_pps_size + in_size + nal_header_size; | |
47 | if ((err = av_reallocp(poutbuf, | |
48 | *poutbuf_size + FF_INPUT_BUFFER_PADDING_SIZE)) < 0) { | |
49 | *poutbuf_size = 0; | |
50 | return err; | |
51 | } | |
52 | if (sps_pps) | |
53 | memcpy(*poutbuf + offset, sps_pps, sps_pps_size); | |
54 | memcpy(*poutbuf + sps_pps_size + nal_header_size + offset, in, in_size); | |
55 | if (!offset) { | |
56 | AV_WB32(*poutbuf + sps_pps_size, 1); | |
57 | } else { | |
58 | (*poutbuf + offset + sps_pps_size)[0] = | |
59 | (*poutbuf + offset + sps_pps_size)[1] = 0; | |
60 | (*poutbuf + offset + sps_pps_size)[2] = 1; | |
61 | } | |
62 | ||
63 | return 0; | |
64 | } | |
65 | ||
f6fa7814 | 66 | static int h264_extradata_to_annexb(H264BSFContext *ctx, AVCodecContext *avctx, const int padding) |
2ba45a60 DM |
67 | { |
68 | uint16_t unit_size; | |
69 | uint64_t total_size = 0; | |
70 | uint8_t *out = NULL, unit_nb, sps_done = 0, | |
71 | sps_seen = 0, pps_seen = 0; | |
72 | const uint8_t *extradata = avctx->extradata + 4; | |
73 | static const uint8_t nalu_header[4] = { 0, 0, 0, 1 }; | |
74 | int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size | |
75 | ||
f6fa7814 DM |
76 | ctx->sps_offset = ctx->pps_offset = -1; |
77 | ||
2ba45a60 DM |
78 | /* retrieve sps and pps unit(s) */ |
79 | unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */ | |
80 | if (!unit_nb) { | |
81 | goto pps; | |
82 | } else { | |
f6fa7814 | 83 | ctx->sps_offset = 0; |
2ba45a60 DM |
84 | sps_seen = 1; |
85 | } | |
86 | ||
87 | while (unit_nb--) { | |
88 | int err; | |
89 | ||
90 | unit_size = AV_RB16(extradata); | |
91 | total_size += unit_size + 4; | |
92 | if (total_size > INT_MAX - padding) { | |
93 | av_log(avctx, AV_LOG_ERROR, | |
94 | "Too big extradata size, corrupted stream or invalid MP4/AVCC bitstream\n"); | |
95 | av_free(out); | |
96 | return AVERROR(EINVAL); | |
97 | } | |
98 | if (extradata + 2 + unit_size > avctx->extradata + avctx->extradata_size) { | |
99 | av_log(avctx, AV_LOG_ERROR, "Packet header is not contained in global extradata, " | |
100 | "corrupted stream or invalid MP4/AVCC bitstream\n"); | |
101 | av_free(out); | |
102 | return AVERROR(EINVAL); | |
103 | } | |
104 | if ((err = av_reallocp(&out, total_size + padding)) < 0) | |
105 | return err; | |
106 | memcpy(out + total_size - unit_size - 4, nalu_header, 4); | |
107 | memcpy(out + total_size - unit_size, extradata + 2, unit_size); | |
108 | extradata += 2 + unit_size; | |
109 | pps: | |
110 | if (!unit_nb && !sps_done++) { | |
111 | unit_nb = *extradata++; /* number of pps unit(s) */ | |
f6fa7814 DM |
112 | if (unit_nb) { |
113 | ctx->pps_offset = (extradata - 1) - (avctx->extradata + 4); | |
2ba45a60 | 114 | pps_seen = 1; |
f6fa7814 | 115 | } |
2ba45a60 DM |
116 | } |
117 | } | |
118 | ||
119 | if (out) | |
f6fa7814 | 120 | memset(out + total_size, 0, padding); |
2ba45a60 DM |
121 | |
122 | if (!sps_seen) | |
123 | av_log(avctx, AV_LOG_WARNING, | |
124 | "Warning: SPS NALU missing or invalid. " | |
125 | "The resulting stream may not play.\n"); | |
126 | ||
127 | if (!pps_seen) | |
128 | av_log(avctx, AV_LOG_WARNING, | |
129 | "Warning: PPS NALU missing or invalid. " | |
130 | "The resulting stream may not play.\n"); | |
131 | ||
132 | av_free(avctx->extradata); | |
133 | avctx->extradata = out; | |
134 | avctx->extradata_size = total_size; | |
135 | ||
136 | return length_size; | |
137 | } | |
138 | ||
139 | static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc, | |
140 | AVCodecContext *avctx, const char *args, | |
141 | uint8_t **poutbuf, int *poutbuf_size, | |
142 | const uint8_t *buf, int buf_size, | |
143 | int keyframe) | |
144 | { | |
145 | H264BSFContext *ctx = bsfc->priv_data; | |
146 | int i; | |
147 | uint8_t unit_type; | |
148 | int32_t nal_size; | |
149 | uint32_t cumul_size = 0; | |
150 | const uint8_t *buf_end = buf + buf_size; | |
151 | int ret = 0; | |
152 | ||
153 | /* nothing to filter */ | |
154 | if (!avctx->extradata || avctx->extradata_size < 6) { | |
155 | *poutbuf = (uint8_t *)buf; | |
156 | *poutbuf_size = buf_size; | |
157 | return 0; | |
158 | } | |
159 | ||
160 | /* retrieve sps and pps NAL units from extradata */ | |
161 | if (!ctx->extradata_parsed) { | |
f6fa7814 | 162 | ret = h264_extradata_to_annexb(ctx, avctx, FF_INPUT_BUFFER_PADDING_SIZE); |
2ba45a60 DM |
163 | if (ret < 0) |
164 | return ret; | |
165 | ctx->length_size = ret; | |
166 | ctx->new_idr = 1; | |
f6fa7814 DM |
167 | ctx->idr_sps_seen = 0; |
168 | ctx->idr_pps_seen = 0; | |
2ba45a60 DM |
169 | ctx->extradata_parsed = 1; |
170 | } | |
171 | ||
172 | *poutbuf_size = 0; | |
173 | *poutbuf = NULL; | |
174 | do { | |
175 | ret= AVERROR(EINVAL); | |
176 | if (buf + ctx->length_size > buf_end) | |
177 | goto fail; | |
178 | ||
179 | for (nal_size = 0, i = 0; i<ctx->length_size; i++) | |
180 | nal_size = (nal_size << 8) | buf[i]; | |
181 | ||
182 | buf += ctx->length_size; | |
183 | unit_type = *buf & 0x1f; | |
184 | ||
185 | if (buf + nal_size > buf_end || nal_size < 0) | |
186 | goto fail; | |
187 | ||
f6fa7814 DM |
188 | if (unit_type == 7) |
189 | ctx->idr_sps_seen = ctx->new_idr = 1; | |
190 | else if (unit_type == 8) { | |
191 | ctx->idr_pps_seen = ctx->new_idr = 1; | |
192 | /* if SPS has not been seen yet, prepend the AVCC one to PPS */ | |
193 | if (!ctx->idr_sps_seen) { | |
194 | if (ctx->sps_offset == -1) | |
195 | av_log(avctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n"); | |
196 | else { | |
197 | if ((ret = alloc_and_copy(poutbuf, poutbuf_size, | |
198 | avctx->extradata + ctx->sps_offset, | |
199 | ctx->pps_offset != -1 ? ctx->pps_offset : avctx->extradata_size - ctx->sps_offset, | |
200 | buf, nal_size)) < 0) | |
201 | goto fail; | |
202 | ctx->idr_sps_seen = 1; | |
203 | goto next_nal; | |
204 | } | |
205 | } | |
206 | } | |
2ba45a60 DM |
207 | |
208 | /* if this is a new IDR picture following an IDR picture, reset the idr flag. | |
209 | * Just check first_mb_in_slice to be 0 as this is the simplest solution. | |
210 | * This could be checking idr_pic_id instead, but would complexify the parsing. */ | |
211 | if (!ctx->new_idr && unit_type == 5 && (buf[1] & 0x80)) | |
212 | ctx->new_idr = 1; | |
213 | ||
214 | /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */ | |
f6fa7814 | 215 | if (ctx->new_idr && unit_type == 5 && !ctx->idr_sps_seen && !ctx->idr_pps_seen) { |
2ba45a60 DM |
216 | if ((ret=alloc_and_copy(poutbuf, poutbuf_size, |
217 | avctx->extradata, avctx->extradata_size, | |
218 | buf, nal_size)) < 0) | |
219 | goto fail; | |
220 | ctx->new_idr = 0; | |
f6fa7814 DM |
221 | /* if only SPS has been seen, also insert PPS */ |
222 | } else if (ctx->new_idr && unit_type == 5 && ctx->idr_sps_seen && !ctx->idr_pps_seen) { | |
223 | if (ctx->pps_offset == -1) { | |
224 | av_log(avctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n"); | |
225 | if ((ret = alloc_and_copy(poutbuf, poutbuf_size, | |
226 | NULL, 0, buf, nal_size)) < 0) | |
227 | goto fail; | |
228 | } else if ((ret = alloc_and_copy(poutbuf, poutbuf_size, | |
229 | avctx->extradata + ctx->pps_offset, avctx->extradata_size - ctx->pps_offset, | |
230 | buf, nal_size)) < 0) | |
231 | goto fail; | |
2ba45a60 DM |
232 | } else { |
233 | if ((ret=alloc_and_copy(poutbuf, poutbuf_size, | |
234 | NULL, 0, buf, nal_size)) < 0) | |
235 | goto fail; | |
236 | if (!ctx->new_idr && unit_type == 1) { | |
237 | ctx->new_idr = 1; | |
f6fa7814 DM |
238 | ctx->idr_sps_seen = 0; |
239 | ctx->idr_pps_seen = 0; | |
2ba45a60 DM |
240 | } |
241 | } | |
242 | ||
f6fa7814 | 243 | next_nal: |
2ba45a60 DM |
244 | buf += nal_size; |
245 | cumul_size += nal_size + ctx->length_size; | |
246 | } while (cumul_size < buf_size); | |
247 | ||
248 | return 1; | |
249 | ||
250 | fail: | |
251 | av_freep(poutbuf); | |
252 | *poutbuf_size = 0; | |
253 | return ret; | |
254 | } | |
255 | ||
256 | AVBitStreamFilter ff_h264_mp4toannexb_bsf = { | |
257 | .name = "h264_mp4toannexb", | |
258 | .priv_data_size = sizeof(H264BSFContext), | |
259 | .filter = h264_mp4toannexb_filter, | |
260 | }; |