ffmpeg/libavformat/libgme.c

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/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* libgme demuxer
*/
#include <gme/gme.h>
#include "libavutil/avstring.h"
#include "libavutil/eval.h"
#include "libavutil/opt.h"
#include "avformat.h"
#include "internal.h"
typedef struct GMEContext {
const AVClass *class;
Music_Emu *music_emu;
gme_info_t *info; ///< selected track
/* options */
int track_index;
int sample_rate;
int64_t max_size;
} GMEContext;
#define OFFSET(x) offsetof(GMEContext, x)
#define A AV_OPT_FLAG_AUDIO_PARAM
#define D AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
{"track_index", "set track that should be played", OFFSET(track_index), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, A|D},
{"sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 44100}, 1000, 999999, A|D},
{"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},
{NULL}
};
static void add_meta(AVFormatContext *s, const char *name, const char *value)
{
if (value && value[0])
av_dict_set(&s->metadata, name, value, 0);
}
static int load_metadata(AVFormatContext *s)
{
GMEContext *gme = s->priv_data;
gme_info_t *info = gme->info;
char buf[30];
add_meta(s, "system", info->system);
add_meta(s, "game", info->game);
add_meta(s, "song", info->song);
add_meta(s, "author", info->author);
add_meta(s, "copyright", info->copyright);
add_meta(s, "comment", info->comment);
add_meta(s, "dumper", info->dumper);
snprintf(buf, sizeof(buf), "%d", (int)gme_track_count(gme->music_emu));
add_meta(s, "tracks", buf);
return 0;
}
#define AUDIO_PKT_SIZE 512
static int read_header_gme(AVFormatContext *s)
{
AVStream *st;
AVIOContext *pb = s->pb;
GMEContext *gme = s->priv_data;
int64_t sz = avio_size(pb);
char *buf;
char dummy;
if (sz < 0) {
av_log(s, AV_LOG_WARNING, "Could not determine file size\n");
sz = gme->max_size;
} else if (gme->max_size && sz > gme->max_size) {
sz = gme->max_size;
}
buf = av_malloc(sz);
if (!buf)
return AVERROR(ENOMEM);
sz = avio_read(pb, buf, sz);
// Data left means our buffer (the max_size option) is too small
if (avio_read(pb, &dummy, 1) == 1) {
av_log(s, AV_LOG_ERROR, "File size is larger than max_size option "
"value %"PRIi64", consider increasing the max_size option\n",
gme->max_size);
return AVERROR_BUFFER_TOO_SMALL;
}
if (gme_open_data(buf, sz, &gme->music_emu, gme->sample_rate)) {
av_freep(&buf);
return AVERROR_INVALIDDATA;
}
av_freep(&buf);
if (gme_track_info(gme->music_emu, &gme->info, gme->track_index))
return AVERROR_STREAM_NOT_FOUND;
if (gme_start_track(gme->music_emu, gme->track_index))
return AVERROR_UNKNOWN;
load_metadata(s);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
avpriv_set_pts_info(st, 64, 1, 1000);
if (st->duration > 0)
st->duration = gme->info->length;
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = AV_NE(AV_CODEC_ID_PCM_S16BE, AV_CODEC_ID_PCM_S16LE);
st->codec->channels = 2;
st->codec->sample_rate = gme->sample_rate;
return 0;
}
static int read_packet_gme(AVFormatContext *s, AVPacket *pkt)
{
GMEContext *gme = s->priv_data;
int n_samples = AUDIO_PKT_SIZE / 2;
int ret;
if (gme_track_ended(gme->music_emu))
return AVERROR_EOF;
if ((ret = av_new_packet(pkt, AUDIO_PKT_SIZE)) < 0)
return ret;
if (gme_play(gme->music_emu, n_samples, (short *)pkt->data))
return AVERROR_EXTERNAL;
pkt->size = AUDIO_PKT_SIZE;
return 0;
}
static int read_close_gme(AVFormatContext *s)
{
GMEContext *gme = s->priv_data;
gme_free_info(gme->info);
gme_delete(gme->music_emu);
return 0;
}
static int read_seek_gme(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
{
GMEContext *gme = s->priv_data;
if (!gme_seek(gme->music_emu, (int)ts))
return AVERROR_EXTERNAL;
return 0;
}
static int probe_gme(AVProbeData *p)
{
// Reads 4 bytes - returns "" if unknown format.
if (gme_identify_header(p->buf)[0]) {
if (p->buf_size < 16384)
return AVPROBE_SCORE_MAX / 4 + 1;
else
return AVPROBE_SCORE_MAX / 2;
}
return 0;
}
static const AVClass class_gme = {
.class_name = "Game Music Emu demuxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_libgme_demuxer = {
.name = "libgme",
.long_name = NULL_IF_CONFIG_SMALL("Game Music Emu demuxer"),
.priv_data_size = sizeof(GMEContext),
.read_probe = probe_gme,
.read_header = read_header_gme,
.read_packet = read_packet_gme,
.read_close = read_close_gme,
.read_seek = read_seek_gme,
.priv_class = &class_gme,
};