FFmpeg
replaygain.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 "internal.h"
37 #include "replaygain.h"
38 
39 static int32_t parse_value(const char *value, int32_t min)
40 {
41  char *fraction;
42  int scale = 10000;
43  int32_t mb = 0;
44  int sign = 1;
45  int db;
46 
47  if (!value)
48  return min;
49 
50  value += strspn(value, " \t");
51 
52  if (*value == '-')
53  sign = -1;
54 
55  db = strtol(value, &fraction, 0);
56  if (*fraction++ == '.') {
57  while (av_isdigit(*fraction) && scale) {
58  mb += scale * (*fraction - '0');
59  scale /= 10;
60  fraction++;
61  }
62  }
63 
64  if (abs(db) > (INT32_MAX - mb) / 100000)
65  return min;
66 
67  return db * 100000 + sign * mb;
68 }
69 
71  int32_t ag, uint32_t ap)
72 {
73  AVReplayGain *replaygain;
74 
75  if (tg == INT32_MIN && ag == INT32_MIN)
76  return 0;
77 
79  sizeof(*replaygain));
80  if (!replaygain)
81  return AVERROR(ENOMEM);
82 
83  replaygain->track_gain = tg;
84  replaygain->track_peak = tp;
85  replaygain->album_gain = ag;
86  replaygain->album_peak = ap;
87 
88  return 0;
89 }
90 
92 {
93  const AVDictionaryEntry *tg, *tp, *ag, *ap;
94 
95  tg = av_dict_get(metadata, "REPLAYGAIN_TRACK_GAIN", NULL, 0);
96  tp = av_dict_get(metadata, "REPLAYGAIN_TRACK_PEAK", NULL, 0);
97  ag = av_dict_get(metadata, "REPLAYGAIN_ALBUM_GAIN", NULL, 0);
98  ap = av_dict_get(metadata, "REPLAYGAIN_ALBUM_PEAK", NULL, 0);
99 
100  return ff_replaygain_export_raw(st,
101  parse_value(tg ? tg->value : NULL, INT32_MIN),
102  parse_value(tp ? tp->value : NULL, 0),
103  parse_value(ag ? ag->value : NULL, INT32_MIN),
104  parse_value(ap ? ap->value : NULL, 0));
105 }
#define NULL
Definition: coverity.c:32
static av_const int av_isdigit(int c)
Locale-independent conversion of ASCII isdigit.
Definition: avstring.h:206
Memory handling functions.
static int32_t parse_value(const char *value, int32_t min)
Definition: replaygain.c:39
uint32_t track_peak
Peak track amplitude, with 100000 representing full scale (but values may overflow).
Definition: replaygain.h:39
Public dictionary API.
#define mb
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:108
#define tg
Definition: regdef.h:74
AVDictionaryEntry * av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key.
Definition: dict.c:40
int ff_replaygain_export(AVStream *st, AVDictionary *metadata)
Parse replaygain tags and export them as per-stream side data.
Definition: replaygain.c:91
int32_t album_gain
Same as track_gain, but for the whole album.
Definition: replaygain.h:43
int32_t
uint8_t * av_stream_new_side_data(AVStream *stream, enum AVPacketSideDataType type, int size)
Allocate new information from stream.
Definition: utils.c:5509
Stream structure.
Definition: avformat.h:881
#define abs(x)
Definition: cuda_runtime.h:35
This side data should be associated with an audio stream and contains ReplayGain information in form ...
Definition: avcodec.h:1245
Main libavformat public API header.
int ff_replaygain_export_raw(AVStream *st, int32_t tg, uint32_t tp, int32_t ag, uint32_t ap)
Export already decoded replaygain values as per-stream side data.
Definition: replaygain.c:70
uint32_t album_peak
Same as track_peak, but for the whole album,.
Definition: replaygain.h:47
char * value
Definition: dict.h:87
int32_t track_gain
Track replay gain in microbels (divide by 100000 to get the value in dB).
Definition: replaygain.h:34
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
ReplayGain information (see http://wiki.hydrogenaudio.org/index.php?title=ReplayGain_1.0_specification).
Definition: replaygain.h:29
float min