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2ba45a60 DM |
1 | /* |
2 | * FLAC common code | |
3 | * Copyright (c) 2009 Justin Ruggles | |
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/channel_layout.h" | |
23 | #include "libavutil/crc.h" | |
24 | #include "libavutil/log.h" | |
25 | #include "bytestream.h" | |
26 | #include "get_bits.h" | |
27 | #include "flac.h" | |
28 | #include "flacdata.h" | |
29 | ||
30 | static const int8_t sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 0 }; | |
31 | ||
32 | static const uint64_t flac_channel_layouts[8] = { | |
33 | AV_CH_LAYOUT_MONO, | |
34 | AV_CH_LAYOUT_STEREO, | |
35 | AV_CH_LAYOUT_SURROUND, | |
36 | AV_CH_LAYOUT_QUAD, | |
37 | AV_CH_LAYOUT_5POINT0, | |
38 | AV_CH_LAYOUT_5POINT1, | |
39 | AV_CH_LAYOUT_6POINT1, | |
40 | AV_CH_LAYOUT_7POINT1 | |
41 | }; | |
42 | ||
43 | static int64_t get_utf8(GetBitContext *gb) | |
44 | { | |
45 | int64_t val; | |
46 | GET_UTF8(val, get_bits(gb, 8), return -1;) | |
47 | return val; | |
48 | } | |
49 | ||
50 | int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb, | |
51 | FLACFrameInfo *fi, int log_level_offset) | |
52 | { | |
53 | int bs_code, sr_code, bps_code; | |
54 | ||
55 | /* frame sync code */ | |
56 | if ((get_bits(gb, 15) & 0x7FFF) != 0x7FFC) { | |
57 | av_log(avctx, AV_LOG_ERROR + log_level_offset, "invalid sync code\n"); | |
58 | return AVERROR_INVALIDDATA; | |
59 | } | |
60 | ||
61 | /* variable block size stream code */ | |
62 | fi->is_var_size = get_bits1(gb); | |
63 | ||
64 | /* block size and sample rate codes */ | |
65 | bs_code = get_bits(gb, 4); | |
66 | sr_code = get_bits(gb, 4); | |
67 | ||
68 | /* channels and decorrelation */ | |
69 | fi->ch_mode = get_bits(gb, 4); | |
70 | if (fi->ch_mode < FLAC_MAX_CHANNELS) { | |
71 | fi->channels = fi->ch_mode + 1; | |
72 | fi->ch_mode = FLAC_CHMODE_INDEPENDENT; | |
73 | } else if (fi->ch_mode < FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE) { | |
74 | fi->channels = 2; | |
75 | fi->ch_mode -= FLAC_MAX_CHANNELS - 1; | |
76 | } else { | |
77 | av_log(avctx, AV_LOG_ERROR + log_level_offset, | |
78 | "invalid channel mode: %d\n", fi->ch_mode); | |
79 | return AVERROR_INVALIDDATA; | |
80 | } | |
81 | ||
82 | /* bits per sample */ | |
83 | bps_code = get_bits(gb, 3); | |
84 | if (bps_code == 3 || bps_code == 7) { | |
85 | av_log(avctx, AV_LOG_ERROR + log_level_offset, | |
86 | "invalid sample size code (%d)\n", | |
87 | bps_code); | |
88 | return AVERROR_INVALIDDATA; | |
89 | } | |
90 | fi->bps = sample_size_table[bps_code]; | |
91 | ||
92 | /* reserved bit */ | |
93 | if (get_bits1(gb)) { | |
94 | av_log(avctx, AV_LOG_ERROR + log_level_offset, | |
95 | "broken stream, invalid padding\n"); | |
96 | return AVERROR_INVALIDDATA; | |
97 | } | |
98 | ||
99 | /* sample or frame count */ | |
100 | fi->frame_or_sample_num = get_utf8(gb); | |
101 | if (fi->frame_or_sample_num < 0) { | |
102 | av_log(avctx, AV_LOG_ERROR + log_level_offset, | |
103 | "sample/frame number invalid; utf8 fscked\n"); | |
104 | return AVERROR_INVALIDDATA; | |
105 | } | |
106 | ||
107 | /* blocksize */ | |
108 | if (bs_code == 0) { | |
109 | av_log(avctx, AV_LOG_ERROR + log_level_offset, | |
110 | "reserved blocksize code: 0\n"); | |
111 | return AVERROR_INVALIDDATA; | |
112 | } else if (bs_code == 6) { | |
113 | fi->blocksize = get_bits(gb, 8) + 1; | |
114 | } else if (bs_code == 7) { | |
115 | fi->blocksize = get_bits(gb, 16) + 1; | |
116 | } else { | |
117 | fi->blocksize = ff_flac_blocksize_table[bs_code]; | |
118 | } | |
119 | ||
120 | /* sample rate */ | |
121 | if (sr_code < 12) { | |
122 | fi->samplerate = ff_flac_sample_rate_table[sr_code]; | |
123 | } else if (sr_code == 12) { | |
124 | fi->samplerate = get_bits(gb, 8) * 1000; | |
125 | } else if (sr_code == 13) { | |
126 | fi->samplerate = get_bits(gb, 16); | |
127 | } else if (sr_code == 14) { | |
128 | fi->samplerate = get_bits(gb, 16) * 10; | |
129 | } else { | |
130 | av_log(avctx, AV_LOG_ERROR + log_level_offset, | |
131 | "illegal sample rate code %d\n", | |
132 | sr_code); | |
133 | return AVERROR_INVALIDDATA; | |
134 | } | |
135 | ||
136 | /* header CRC-8 check */ | |
137 | skip_bits(gb, 8); | |
138 | if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer, | |
139 | get_bits_count(gb)/8)) { | |
140 | av_log(avctx, AV_LOG_ERROR + log_level_offset, | |
141 | "header crc mismatch\n"); | |
142 | return AVERROR_INVALIDDATA; | |
143 | } | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | int ff_flac_get_max_frame_size(int blocksize, int ch, int bps) | |
149 | { | |
150 | /* Technically, there is no limit to FLAC frame size, but an encoder | |
151 | should not write a frame that is larger than if verbatim encoding mode | |
152 | were to be used. */ | |
153 | ||
154 | int count; | |
155 | ||
156 | count = 16; /* frame header */ | |
157 | count += ch * ((7+bps+7)/8); /* subframe headers */ | |
158 | if (ch == 2) { | |
159 | /* for stereo, need to account for using decorrelation */ | |
160 | count += (( 2*bps+1) * blocksize + 7) / 8; | |
161 | } else { | |
162 | count += ( ch*bps * blocksize + 7) / 8; | |
163 | } | |
164 | count += 2; /* frame footer */ | |
165 | ||
166 | return count; | |
167 | } | |
168 | ||
f6fa7814 | 169 | int ff_flac_is_extradata_valid(AVCodecContext *avctx, |
2ba45a60 DM |
170 | enum FLACExtradataFormat *format, |
171 | uint8_t **streaminfo_start) | |
172 | { | |
173 | if (!avctx->extradata || avctx->extradata_size < FLAC_STREAMINFO_SIZE) { | |
174 | av_log(avctx, AV_LOG_ERROR, "extradata NULL or too small.\n"); | |
175 | return 0; | |
176 | } | |
177 | if (AV_RL32(avctx->extradata) != MKTAG('f','L','a','C')) { | |
178 | /* extradata contains STREAMINFO only */ | |
179 | if (avctx->extradata_size != FLAC_STREAMINFO_SIZE) { | |
180 | av_log(avctx, AV_LOG_WARNING, "extradata contains %d bytes too many.\n", | |
181 | FLAC_STREAMINFO_SIZE-avctx->extradata_size); | |
182 | } | |
183 | *format = FLAC_EXTRADATA_FORMAT_STREAMINFO; | |
184 | *streaminfo_start = avctx->extradata; | |
185 | } else { | |
186 | if (avctx->extradata_size < 8+FLAC_STREAMINFO_SIZE) { | |
187 | av_log(avctx, AV_LOG_ERROR, "extradata too small.\n"); | |
188 | return 0; | |
189 | } | |
190 | *format = FLAC_EXTRADATA_FORMAT_FULL_HEADER; | |
191 | *streaminfo_start = &avctx->extradata[8]; | |
192 | } | |
193 | return 1; | |
194 | } | |
195 | ||
196 | void ff_flac_set_channel_layout(AVCodecContext *avctx) | |
197 | { | |
198 | if (avctx->channels <= FF_ARRAY_ELEMS(flac_channel_layouts)) | |
199 | avctx->channel_layout = flac_channel_layouts[avctx->channels - 1]; | |
200 | else | |
201 | avctx->channel_layout = 0; | |
202 | } | |
203 | ||
f6fa7814 | 204 | void ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s, |
2ba45a60 DM |
205 | const uint8_t *buffer) |
206 | { | |
207 | GetBitContext gb; | |
208 | init_get_bits(&gb, buffer, FLAC_STREAMINFO_SIZE*8); | |
209 | ||
210 | skip_bits(&gb, 16); /* skip min blocksize */ | |
211 | s->max_blocksize = get_bits(&gb, 16); | |
212 | if (s->max_blocksize < FLAC_MIN_BLOCKSIZE) { | |
213 | av_log(avctx, AV_LOG_WARNING, "invalid max blocksize: %d\n", | |
214 | s->max_blocksize); | |
215 | s->max_blocksize = 16; | |
216 | } | |
217 | ||
218 | skip_bits(&gb, 24); /* skip min frame size */ | |
219 | s->max_framesize = get_bits_long(&gb, 24); | |
220 | ||
221 | s->samplerate = get_bits_long(&gb, 20); | |
222 | s->channels = get_bits(&gb, 3) + 1; | |
223 | s->bps = get_bits(&gb, 5) + 1; | |
224 | ||
225 | avctx->channels = s->channels; | |
226 | avctx->sample_rate = s->samplerate; | |
227 | avctx->bits_per_raw_sample = s->bps; | |
228 | ||
229 | if (!avctx->channel_layout || | |
230 | av_get_channel_layout_nb_channels(avctx->channel_layout) != avctx->channels) | |
231 | ff_flac_set_channel_layout(avctx); | |
232 | ||
233 | s->samples = get_bits64(&gb, 36); | |
234 | ||
235 | skip_bits_long(&gb, 64); /* md5 sum */ | |
236 | skip_bits_long(&gb, 64); /* md5 sum */ | |
237 | } | |
f6fa7814 DM |
238 | |
239 | #if LIBAVCODEC_VERSION_MAJOR < 57 | |
240 | void avpriv_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s, | |
241 | const uint8_t *buffer) | |
242 | { | |
243 | ff_flac_parse_streaminfo(avctx, s, buffer); | |
244 | } | |
245 | ||
246 | int avpriv_flac_is_extradata_valid(AVCodecContext *avctx, | |
247 | enum FLACExtradataFormat *format, | |
248 | uint8_t **streaminfo_start) | |
249 | { | |
250 | return ff_flac_is_extradata_valid(avctx, format, streaminfo_start); | |
251 | } | |
252 | #endif |