FFmpeg
libgme.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 * 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 (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;
169 
170  return 0;
171 }
172 
173 static int read_seek_gme(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
174 {
175  GMEContext *gme = s->priv_data;
176  if (!gme_seek(gme->music_emu, (int)ts))
177  return AVERROR_EXTERNAL;
178  return 0;
179 }
180 
181 static int probe_gme(const AVProbeData *p)
182 {
183  // Reads 4 bytes - returns "" if unknown format.
184  if (gme_identify_header(p->buf)[0]) {
185  if (p->buf_size < 16384)
186  return AVPROBE_SCORE_MAX / 4 ;
187  else
188  return AVPROBE_SCORE_MAX / 2;
189  }
190  return 0;
191 }
192 
193 static const AVClass class_gme = {
194  .class_name = "Game Music Emu demuxer",
195  .item_name = av_default_item_name,
196  .option = options,
197  .version = LIBAVUTIL_VERSION_INT,
198 };
199 
201  .name = "libgme",
202  .long_name = NULL_IF_CONFIG_SMALL("Game Music Emu demuxer"),
203  .priv_data_size = sizeof(GMEContext),
209  .priv_class = &class_gme,
210 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:342
AVOption.
Definition: opt.h:248
#define OFFSET(x)
Definition: libgme.c:41
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
#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:4999
static int load_metadata(AVFormatContext *s, int64_t *duration)
Definition: libgme.c:57
static const AVOption options[]
Definition: libgme.c:44
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
int sample_rate
Definition: libgme.c:37
static int read_packet_gme(AVFormatContext *s, AVPacket *pkt)
Definition: libgme.c:155
AVPacket * pkt
Definition: movenc.c:59
#define A
Definition: libgme.c:42
static int read_header_gme(AVFormatContext *s)
Definition: libgme.c:91
Format I/O context.
Definition: avformat.h:1247
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
#define av_malloc(s)
AVOptions.
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:108
#define AV_NE(be, le)
Definition: common.h:50
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4553
int64_t duration
Definition: movenc.c:64
uint8_t * data
Definition: packet.h:369
#define D
Definition: libgme.c:43
#define AVERROR_EOF
End of file.
Definition: error.h:55
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:633
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
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1489
Music_Emu * music_emu
Definition: libgme.c:33
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:117
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
static void add_meta(AVFormatContext *s, const char *name, const char *value)
Definition: libgme.c:51
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
MIPS optimizations info
Definition: mips.txt:2
#define AVERROR_BUFFER_TOO_SMALL
Buffer too small.
Definition: error.h:51
#define s(width, name)
Definition: cbs_vp9.c:257
int dummy
Definition: motion.c:64
static int probe_gme(const AVProbeData *p)
Definition: libgme.c:181
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
Stream structure.
Definition: avformat.h:884
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVIOContext * pb
I/O context.
Definition: avformat.h:1289
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
int64_t max_size
Definition: libgme.c:38
Describe the class of an AVClass context structure.
Definition: log.h:67
#define snprintf
Definition: snprintf.h:34
#define AUDIO_PKT_SIZE
Definition: libgme.c:82
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
#define flags(name, subs,...)
Definition: cbs_av1.c:561
static const AVClass class_gme
Definition: libgme.c:193
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:933
int sample_rate
Audio only.
Definition: codec_par.h:170
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
Main libavformat public API header.
AVInputFormat ff_libgme_demuxer
Definition: libgme.c:200
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:71
void * priv_data
Format private data.
Definition: avformat.h:1275
#define AVERROR_STREAM_NOT_FOUND
Stream not found.
Definition: error.h:65
int track_index
Definition: libgme.c:36
int channels
Audio only.
Definition: codec_par.h:166
#define av_freep(p)
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
static int read_seek_gme(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
Definition: libgme.c:173
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1049
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
#define AVERROR_EXTERNAL
Generic error in an external library.
Definition: error.h:57
This structure stores compressed data.
Definition: packet.h:346
simple arithmetic expression evaluator
const char * name
Definition: opengl_enc.c:102
static int read_close_gme(AVFormatContext *s)
Definition: libgme.c:84