replaygain: remove unused variable
[libav.git] / libavformat / replaygain.c
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1/*
2 * This file is part of Libav.
3 *
4 * Libav is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * Libav is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with Libav; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19/**
20 * @file
21 * replaygain tags parsing
22 */
23
24#include <stdint.h>
25#include <stdlib.h>
26#include <string.h>
27
28#include "libavutil/avstring.h"
29#include "libavutil/dict.h"
30#include "libavutil/intreadwrite.h"
31#include "libavutil/mathematics.h"
32#include "libavutil/mem.h"
33#include "libavutil/replaygain.h"
34
35#include "avformat.h"
36#include "replaygain.h"
37
8542f9c4 38static int32_t parse_value(const char *value, int32_t min)
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39{
40 char *fraction;
41 int scale = 10000;
42 int32_t mb = 0;
25b6837f 43 int sign = 1;
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44 int db;
45
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46 if (!value)
47 return min;
5a7e35dd 48
8542f9c4 49 value += strspn(value, " \t");
5a7e35dd 50
8542f9c4 51 if (*value == '-')
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52 sign = -1;
53
8542f9c4 54 db = strtol(value, &fraction, 0);
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55 if (*fraction++ == '.') {
56 while (av_isdigit(*fraction) && scale) {
57 mb += scale * (*fraction - '0');
58 scale /= 10;
59 fraction++;
60 }
61 }
62
63 if (abs(db) > (INT32_MAX - mb) / 100000)
8542f9c4 64 return min;
5a7e35dd 65
25b6837f 66 return db * 100000 + sign * mb;
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67}
68
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69static int replaygain_export(AVStream *st,
70 const uint8_t *track_gain, const uint8_t *track_peak,
71 const uint8_t *album_gain, const uint8_t *album_peak)
72{
73 AVPacketSideData *sd, *tmp;
74 AVReplayGain *replaygain;
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75 int32_t tg, ag;
76 uint32_t tp, ap;
77
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78 tg = parse_value(track_gain, INT32_MIN);
79 ag = parse_value(album_gain, INT32_MIN);
80 tp = parse_value(track_peak, 0);
81 ap = parse_value(album_peak, 0);
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82
83 if (tg == INT32_MIN && ag == INT32_MIN)
84 return 0;
85
86 replaygain = av_mallocz(sizeof(*replaygain));
87 if (!replaygain)
88 return AVERROR(ENOMEM);
89
90 tmp = av_realloc_array(st->side_data, st->nb_side_data + 1, sizeof(*tmp));
91 if (!tmp) {
92 av_freep(&replaygain);
93 return AVERROR(ENOMEM);
94 }
95 st->side_data = tmp;
96 st->nb_side_data++;
97
98 sd = &st->side_data[st->nb_side_data - 1];
99 sd->type = AV_PKT_DATA_REPLAYGAIN;
100 sd->data = (uint8_t*)replaygain;
101 sd->size = sizeof(*replaygain);
102
103 replaygain->track_gain = tg;
104 replaygain->track_peak = tp;
105 replaygain->album_gain = ag;
106 replaygain->album_peak = ap;
107
108 return 0;
109}
110
111int ff_replaygain_export(AVStream *st, AVDictionary *metadata)
112{
113 const AVDictionaryEntry *tg, *tp, *ag, *ap;
114
115 tg = av_dict_get(metadata, "REPLAYGAIN_TRACK_GAIN", NULL, 0);
116 tp = av_dict_get(metadata, "REPLAYGAIN_TRACK_PEAK", NULL, 0);
117 ag = av_dict_get(metadata, "REPLAYGAIN_ALBUM_GAIN", NULL, 0);
118 ap = av_dict_get(metadata, "REPLAYGAIN_ALBUM_PEAK", NULL, 0);
119
120 return replaygain_export(st,
121 tg ? tg->value : NULL,
122 tp ? tp->value : NULL,
123 ag ? ag->value : NULL,
124 ap ? ap->value : NULL);
125}