FFmpeg  4.4
libgme.c
Go to the documentation of this file.
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 * libgme demuxer
22 */
23 
24 #include <gme/gme.h>
25 #include "libavutil/avstring.h"
26 #include "libavutil/eval.h"
27 #include "libavutil/opt.h"
28 #include "avformat.h"
29 #include "internal.h"
30 
31 typedef struct GMEContext {
32  const AVClass *class;
33  Music_Emu *music_emu;
34 
35  /* options */
38  int64_t max_size;
39 } GMEContext;
40 
41 #define OFFSET(x) offsetof(GMEContext, x)
42 #define A AV_OPT_FLAG_AUDIO_PARAM
43 #define D AV_OPT_FLAG_DECODING_PARAM
44 static const AVOption options[] = {
45  {"track_index", "set track that should be played", OFFSET(track_index), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, A|D},
46  {"sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 44100}, 1000, 999999, A|D},
47  {"max_size", "set max file size supported (in bytes)", OFFSET(max_size), AV_OPT_TYPE_INT64, {.i64 = 50 * 1024 * 1024}, 0, SIZE_MAX, A|D},
48  {NULL}
49 };
50 
51 static void add_meta(AVFormatContext *s, const char *name, const char *value)
52 {
53  if (value && value[0])
54  av_dict_set(&s->metadata, name, value, 0);
55 }
56 
57 static int load_metadata(AVFormatContext *s, int64_t *duration)
58 {
59  GMEContext *gme = s->priv_data;
60  gme_info_t *info = NULL;
61  char buf[30];
62 
63  if (gme_track_info(gme->music_emu, &info, gme->track_index))
65 
66  *duration = info->length;
67  add_meta(s, "system", info->system);
68  add_meta(s, "game", info->game);
69  add_meta(s, "song", info->song);
70  add_meta(s, "author", info->author);
71  add_meta(s, "copyright", info->copyright);
72  add_meta(s, "comment", info->comment);
73  add_meta(s, "dumper", info->dumper);
74 
75  snprintf(buf, sizeof(buf), "%d", (int)gme_track_count(gme->music_emu));
76  add_meta(s, "tracks", buf);
77  gme_free_info(info);
78 
79  return 0;
80 }
81 
82 #define AUDIO_PKT_SIZE 512
83 
85 {
86  GMEContext *gme = s->priv_data;
87  gme_delete(gme->music_emu);
88  return 0;
89 }
90 
92 {
93  AVStream *st;
94  AVIOContext *pb = s->pb;
95  GMEContext *gme = s->priv_data;
96  int64_t sz = avio_size(pb);
97  int64_t duration;
98  char *buf;
99  char dummy;
100  int ret;
101 
102  if (sz < 0) {
103  av_log(s, AV_LOG_WARNING, "Could not determine file size\n");
104  sz = gme->max_size;
105  } else if (gme->max_size && sz > gme->max_size) {
106  sz = gme->max_size;
107  }
108 
109  buf = av_malloc(sz);
110  if (!buf)
111  return AVERROR(ENOMEM);
112  sz = avio_read(pb, buf, sz);
113 
114  // Data left means our buffer (the max_size option) is too small
115  if (avio_read(pb, &dummy, 1) == 1) {
116  av_log(s, AV_LOG_ERROR, "File size is larger than max_size option "
117  "value %"PRIi64", consider increasing the max_size option\n",
118  gme->max_size);
119  av_freep(&buf);
121  }
122 
123  if (gme_open_data(buf, sz, &gme->music_emu, gme->sample_rate)) {
124  av_freep(&buf);
125  return AVERROR_INVALIDDATA;
126  }
127  av_freep(&buf);
128 
129  ret = load_metadata(s, &duration);
130  if (ret < 0) {
131  read_close_gme(s);
132  return ret;
133  }
134  if (gme_start_track(gme->music_emu, gme->track_index)) {
135  read_close_gme(s);
136  return AVERROR_UNKNOWN;
137  }
138 
139  st = avformat_new_stream(s, NULL);
140  if (!st) {
141  read_close_gme(s);
142  return AVERROR(ENOMEM);
143  }
144  avpriv_set_pts_info(st, 64, 1, 1000);
145  if (st->duration > 0)
146  st->duration = duration;
149  st->codecpar->channels = 2;
150  st->codecpar->sample_rate = gme->sample_rate;
151 
152  return 0;
153 }
154 
156 {
157  GMEContext *gme = s->priv_data;
158  int n_samples = AUDIO_PKT_SIZE / 2;
159  int ret;
160 
161  if (gme_track_ended(gme->music_emu))
162  return AVERROR_EOF;
163 
164  if ((ret = av_new_packet(pkt, AUDIO_PKT_SIZE)) < 0)
165  return ret;
166 
167  if (gme_play(gme->music_emu, n_samples, (short *)pkt->data))
168  return AVERROR_EXTERNAL;
170 
171  return 0;
172 }
173 
174 static int read_seek_gme(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
175 {
176  GMEContext *gme = s->priv_data;
177  if (!gme_seek(gme->music_emu, (int)ts))
178  return AVERROR_EXTERNAL;
179  return 0;
180 }
181 
182 static int probe_gme(const AVProbeData *p)
183 {
184  // Reads 4 bytes - returns "" if unknown format.
185  if (gme_identify_header(p->buf)[0]) {
186  if (p->buf_size < 16384)
187  return AVPROBE_SCORE_MAX / 4 ;
188  else
189  return AVPROBE_SCORE_MAX / 2;
190  }
191  return 0;
192 }
193 
194 static const AVClass class_gme = {
195  .class_name = "Game Music Emu demuxer",
196  .item_name = av_default_item_name,
197  .option = options,
198  .version = LIBAVUTIL_VERSION_INT,
199 };
200 
202  .name = "libgme",
203  .long_name = NULL_IF_CONFIG_SMALL("Game Music Emu demuxer"),
204  .priv_data_size = sizeof(GMEContext),
210  .priv_class = &class_gme,
211 };
Main libavformat public API header.
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:342
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:633
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
#define flags(name, subs,...)
Definition: cbs_av1.c:561
#define s(width, name)
Definition: cbs_vp9.c:257
#define AV_NE(be, le)
Definition: common.h:50
#define NULL
Definition: coverity.c:32
double value
Definition: eval.c:98
simple arithmetic expression evaluator
sample_rate
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
@ AV_OPT_TYPE_INT64
Definition: opt.h:226
@ AV_OPT_TYPE_INT
Definition: opt.h:225
@ AV_CODEC_ID_PCM_S16LE
Definition: codec_id.h:313
@ AV_CODEC_ID_PCM_S16BE
Definition: codec_id.h:314
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:99
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4505
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:71
#define AVERROR_BUFFER_TOO_SMALL
Buffer too small.
Definition: error.h:51
#define AVERROR_EXTERNAL
Generic error in an external library.
Definition: error.h:57
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR_STREAM_NOT_FOUND
Stream not found.
Definition: error.h:65
#define AVERROR_EOF
End of file.
Definition: error.h:55
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4941
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
static const AVOption options[]
Definition: libgme.c:44
#define AUDIO_PKT_SIZE
Definition: libgme.c:82
static int load_metadata(AVFormatContext *s, int64_t *duration)
Definition: libgme.c:57
static int read_seek_gme(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
Definition: libgme.c:174
AVInputFormat ff_libgme_demuxer
Definition: libgme.c:201
#define A
Definition: libgme.c:42
static int read_header_gme(AVFormatContext *s)
Definition: libgme.c:91
static int probe_gme(const AVProbeData *p)
Definition: libgme.c:182
static int read_close_gme(AVFormatContext *s)
Definition: libgme.c:84
static int read_packet_gme(AVFormatContext *s, AVPacket *pkt)
Definition: libgme.c:155
#define OFFSET(x)
Definition: libgme.c:41
static void add_meta(AVFormatContext *s, const char *name, const char *value)
Definition: libgme.c:51
#define D
Definition: libgme.c:43
static const AVClass class_gme
Definition: libgme.c:194
int dummy
Definition: motion.c:64
AVOptions.
const char * name
Definition: qsvenc.c:46
#define snprintf
Definition: snprintf.h:34
Describe the class of an AVClass context structure.
Definition: log.h:67
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
int channels
Audio only.
Definition: codec_par.h:166
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
int sample_rate
Audio only.
Definition: codec_par.h:170
Format I/O context.
Definition: avformat.h:1232
Bytestream IO Context.
Definition: avio.h:161
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
AVOption.
Definition: opt.h:248
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:922
int sample_rate
Definition: libgme.c:37
int64_t max_size
Definition: libgme.c:38
int track_index
Definition: libgme.c:36
Music_Emu * music_emu
Definition: libgme.c:33
#define av_freep(p)
#define av_malloc(s)
#define av_log(a,...)
int64_t duration
Definition: movenc.c:64
AVPacket * pkt
Definition: movenc.c:59
static int track_index(VividasDemuxContext *viv, AVFormatContext *s, uint8_t *buf, unsigned size)
Definition: vividas.c:434