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 
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 };
AV_CODEC_ID_PCM_S16LE
@ AV_CODEC_ID_PCM_S16LE
Definition: codec_id.h:313
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
read_packet_gme
static int read_packet_gme(AVFormatContext *s, AVPacket *pkt)
Definition: libgme.c:155
name
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option name
Definition: writing_filters.txt:88
AVERROR
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
opt.h
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4553
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
track_index
static int track_index(VividasDemuxContext *viv, AVFormatContext *s, uint8_t *buf, unsigned size)
Definition: vividas.c:434
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
add_meta
static void add_meta(AVFormatContext *s, const char *name, const char *value)
Definition: libgme.c:51
AVPacket::data
uint8_t * data
Definition: packet.h:369
read_header_gme
static int read_header_gme(AVFormatContext *s)
Definition: libgme.c:91
AVOption
AVOption.
Definition: opt.h:248
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:71
avio_size
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:342
sample_rate
sample_rate
Definition: ffmpeg_filter.c:158
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
GMEContext::sample_rate
int sample_rate
Definition: libgme.c:37
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
AV_CODEC_ID_PCM_S16BE
@ AV_CODEC_ID_PCM_S16BE
Definition: codec_id.h:314
read_seek
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
GMEContext
Definition: libgme.c:31
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
AVERROR_BUFFER_TOO_SMALL
#define AVERROR_BUFFER_TOO_SMALL
Buffer too small.
Definition: error.h:51
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:922
load_metadata
static int load_metadata(AVFormatContext *s, int64_t *duration)
Definition: libgme.c:57
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
AVInputFormat
Definition: avformat.h:640
D
#define D
Definition: libgme.c:43
duration
int64_t duration
Definition: movenc.c:64
OFFSET
#define OFFSET(x)
Definition: libgme.c:41
s
#define s(width, name)
Definition: cbs_vp9.c:257
av_new_packet
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
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
info
MIPS optimizations info
Definition: mips.txt:2
AV_OPT_TYPE_INT64
@ AV_OPT_TYPE_INT64
Definition: opt.h:226
AUDIO_PKT_SIZE
#define AUDIO_PKT_SIZE
Definition: libgme.c:82
GMEContext::track_index
int track_index
Definition: libgme.c:36
AVFormatContext
Format I/O context.
Definition: avformat.h:1231
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:67
options
static const AVOption options[]
Definition: libgme.c:44
NULL
#define NULL
Definition: coverity.c:32
read_probe
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
GMEContext::music_emu
Music_Emu * music_emu
Definition: libgme.c:33
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
ff_libgme_demuxer
AVInputFormat ff_libgme_demuxer
Definition: libgme.c:200
class_gme
static const AVClass class_gme
Definition: libgme.c:193
eval.h
read_close_gme
static int read_close_gme(AVFormatContext *s)
Definition: libgme.c:84
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
avpriv_set_pts_info
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
AV_NE
#define AV_NE(be, le)
Definition: common.h:50
AVERROR_EXTERNAL
#define AVERROR_EXTERNAL
Generic error in an external library.
Definition: error.h:57
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
GMEContext::max_size
int64_t max_size
Definition: libgme.c:38
ret
ret
Definition: filter_design.txt:187
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVStream
Stream structure.
Definition: avformat.h:873
AVClass::class_name
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
avformat.h
AVERROR_STREAM_NOT_FOUND
#define AVERROR_STREAM_NOT_FOUND
Stream not found.
Definition: error.h:65
dummy
int dummy
Definition: motion.c:64
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:633
probe_gme
static int probe_gme(const AVProbeData *p)
Definition: libgme.c:181
read_seek_gme
static int read_seek_gme(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
Definition: libgme.c:173
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:346
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
av_dict_set
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
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
avstring.h
A
#define A
Definition: libgme.c:42
snprintf
#define snprintf
Definition: snprintf.h:34