libavformat/libgme.c

   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/mem.h"
  26 #include "libavutil/opt.h"
  27 #include "avformat.h"
  28 #include "demux.h"
  29 #include "internal.h"
  30
  31 typedef struct GMEContext {
  32     const AVClass *class;
  33     Music_Emu *music_emu;
  34
  35     /* options */
  36     int track_index;
  37     int sample_rate;
  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))
  64         return AVERROR_STREAM_NOT_FOUND;
  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
  84 static int read_close_gme(AVFormatContext *s)
  85 {
  86     GMEContext *gme = s->priv_data;
  87     if (gme->music_emu)
  88         gme_delete(gme->music_emu);
  89     return 0;
  90 }
  91
  92 static int read_header_gme(AVFormatContext *s)
  93 {
  94     AVStream *st;
  95     AVIOContext *pb = s->pb;
  96     GMEContext *gme = s->priv_data;
  97     int64_t sz = avio_size(pb);
  98     int64_t duration;
  99     char *buf;
 100     char dummy;
 101     int ret;
 102
 103     if (sz < 0) {
 104         av_log(s, AV_LOG_WARNING, "Could not determine file size\n");
 105         sz = gme->max_size;
 106     } else if (gme->max_size && sz > gme->max_size) {
 107         sz = gme->max_size;
 108     }
 109
 110     buf = av_malloc(sz);
 111     if (!buf)
 112         return AVERROR(ENOMEM);
 113     sz = avio_read(pb, buf, sz);
 114
 115     // Data left means our buffer (the max_size option) is too small
 116     if (avio_read(pb, &dummy, 1) == 1) {
 117         av_log(s, AV_LOG_ERROR, "File size is larger than max_size option "
 118                "value %"PRIi64", consider increasing the max_size option\n",
 119                gme->max_size);
 120         av_freep(&buf);
 121         return AVERROR_BUFFER_TOO_SMALL;
 122     }
 123
 124     if (gme_open_data(buf, sz, &gme->music_emu, gme->sample_rate)) {
 125         gme->music_emu = NULL; /* Just for safety */
 126         av_freep(&buf);
 127         return AVERROR_INVALIDDATA;
 128     }
 129     av_freep(&buf);
 130
 131     ret = load_metadata(s, &duration);
 132     if (ret < 0)
 133         return ret;
 134     if (gme_start_track(gme->music_emu, gme->track_index))
 135         return AVERROR_UNKNOWN;
 136
 137     st = avformat_new_stream(s, NULL);
 138     if (!st)
 139         return AVERROR(ENOMEM);
 140     avpriv_set_pts_info(st, 64, 1, 1000);
 141     if (duration > 0)
 142         st->duration = duration;
 143     st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
 144     st->codecpar->codec_id    = AV_NE(AV_CODEC_ID_PCM_S16BE, AV_CODEC_ID_PCM_S16LE);
 145     st->codecpar->ch_layout.nb_channels = 2;
 146     st->codecpar->sample_rate = gme->sample_rate;
 147
 148     return 0;
 149 }
 150
 151 static int read_packet_gme(AVFormatContext *s, AVPacket *pkt)
 152 {
 153     GMEContext *gme = s->priv_data;
 154     int n_samples = AUDIO_PKT_SIZE / 2;
 155     int ret;
 156
 157     if (gme_track_ended(gme->music_emu))
 158         return AVERROR_EOF;
 159
 160     if ((ret = av_new_packet(pkt, AUDIO_PKT_SIZE)) < 0)
 161         return ret;
 162
 163     if (gme_play(gme->music_emu, n_samples, (short *)pkt->data))
 164         return AVERROR_EXTERNAL;
 165
 166     return 0;
 167 }
 168
 169 static int read_seek_gme(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
 170 {
 171     GMEContext *gme = s->priv_data;
 172     if (!gme_seek(gme->music_emu, (int)ts))
 173         return AVERROR_EXTERNAL;
 174     return 0;
 175 }
 176
 177 static int probe_gme(const AVProbeData *p)
 178 {
 179     // Reads 4 bytes - returns "" if unknown format.
 180     if (gme_identify_header(p->buf)[0]) {
 181         if (p->buf_size < 16384)
 182             return AVPROBE_SCORE_MAX / 4 ;
 183         else
 184             return AVPROBE_SCORE_MAX / 2;
 185     }
 186     return 0;
 187 }
 188
 189 static const AVClass class_gme = {
 190     .class_name = "Game Music Emu demuxer",
 191     .item_name  = av_default_item_name,
 192     .option     = options,
 193     .version    = LIBAVUTIL_VERSION_INT,
 194 };
 195
 196 const FFInputFormat ff_libgme_demuxer = {
 197     .p.name         = "libgme",
 198     .p.long_name    = NULL_IF_CONFIG_SMALL("Game Music Emu demuxer"),
 199     .p.priv_class   = &class_gme,
 200     .priv_data_size = sizeof(GMEContext),
 201     .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,
 202     .read_probe     = probe_gme,
 203     .read_header    = read_header_gme,
 204     .read_packet    = read_packet_gme,
 205     .read_close     = read_close_gme,
 206     .read_seek      = read_seek_gme,
 207 };