/src/ffmpeg/libavformat/alp.c

Source
/*
 * LEGO Racers ALP (.tun & .pcm) (de)muxer
 *
 * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com)
 *
 * 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
 */

#include "config_components.h"

#include "libavutil/channel_layout.h"
#include "avformat.h"
#include "avio_internal.h"
#include "demux.h"
#include "internal.h"
#include "mux.h"
#include "rawenc.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/internal.h"
#include "libavutil/opt.h"

#define ALP_TAG            MKTAG('A', 'L', 'P', ' ')
#define ALP_MAX_READ_SIZE  4096

typedef struct ALPHeader {
    uint32_t    magic;          /*< Magic Number, {'A', 'L', 'P', ' '} */
    uint32_t    header_size;    /*< Header size (after this). */
    char        adpcm[6];       /*< "ADPCM" */
    uint8_t     unk1;           /*< Unknown */
    uint8_t     num_channels;   /*< Channel Count. */
    uint32_t    sample_rate;    /*< Sample rate, only if header_size >= 12. */
} ALPHeader;

typedef enum ALPType {
    ALP_TYPE_AUTO = 0, /*< Autodetect based on file extension. */
    ALP_TYPE_TUN  = 1, /*< Force a .TUN file. */
    ALP_TYPE_PCM  = 2, /*< Force a .PCM file. */
} ALPType;

typedef struct ALPMuxContext {
    const AVClass *class;
    ALPType type;
} ALPMuxContext;

#if CONFIG_ALP_DEMUXER
static int alp_probe(const AVProbeData *p)
{
    uint32_t i;

    if (AV_RL32(p->buf) != ALP_TAG)
        return 0;

    /* Only allowed header sizes are 8 and 12. */
    i = AV_RL32(p->buf + 4);
    if (i != 8 && i != 12)
        return 0;

    if (strncmp("ADPCM", p->buf + 8, 6) != 0)
        return 0;

    return AVPROBE_SCORE_MAX - 1;
}

static int alp_read_header(AVFormatContext *s)
{
    int ret;
    AVStream *st;
    ALPHeader *hdr = s->priv_data;
    AVCodecParameters *par;

    if ((hdr->magic = avio_rl32(s->pb)) != ALP_TAG)
        return AVERROR_INVALIDDATA;

    hdr->header_size = avio_rl32(s->pb);

    if (hdr->header_size != 8 && hdr->header_size != 12) {
        return AVERROR_INVALIDDATA;
    }

    if ((ret = ffio_read_size(s->pb, hdr->adpcm, sizeof(hdr->adpcm))) < 0)
        return ret;

    if (strncmp("ADPCM", hdr->adpcm, sizeof(hdr->adpcm)) != 0)
        return AVERROR_INVALIDDATA;

    hdr->unk1                   = avio_r8(s->pb);
    hdr->num_channels           = avio_r8(s->pb);

    if (hdr->header_size == 8) {
        /* .TUN music file */
        hdr->sample_rate        = 22050;

    } else {
        /* .PCM sound file */
        hdr->sample_rate        = avio_rl32(s->pb);
    }

    if (hdr->sample_rate > 44100) {
        avpriv_request_sample(s, "Sample Rate > 44100");
        return AVERROR_PATCHWELCOME;
    }

    if (!(st = avformat_new_stream(s, NULL)))
        return AVERROR(ENOMEM);

    par                         = st->codecpar;
    par->codec_type             = AVMEDIA_TYPE_AUDIO;
    par->codec_id               = AV_CODEC_ID_ADPCM_IMA_ALP;
    par->format                 = AV_SAMPLE_FMT_S16;
    par->sample_rate            = hdr->sample_rate;

    if (hdr->num_channels > 2 || hdr->num_channels == 0)
        return AVERROR_INVALIDDATA;

    av_channel_layout_default(&par->ch_layout, hdr->num_channels);
    par->bits_per_coded_sample  = 4;
    par->block_align            = 1;
    par->bit_rate               = par->ch_layout.nb_channels *
                                  par->sample_rate *
                                  par->bits_per_coded_sample;

    avpriv_set_pts_info(st, 64, 1, par->sample_rate);
    return 0;
}

static int alp_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    int ret;
    AVCodecParameters *par = s->streams[0]->codecpar;

    if ((ret = av_get_packet(s->pb, pkt, ALP_MAX_READ_SIZE)) < 0)
        return ret;

    pkt->flags         &= ~AV_PKT_FLAG_CORRUPT;
    pkt->stream_index   = 0;
    pkt->duration       = ret * 2 / par->ch_layout.nb_channels;

    return 0;
}

static int alp_seek(AVFormatContext *s, int stream_index,
                     int64_t pts, int flags)
{
    const ALPHeader *hdr = s->priv_data;

    if (pts != 0)
        return AVERROR(EINVAL);

    return avio_seek(s->pb, hdr->header_size + 8, SEEK_SET);
}

const FFInputFormat ff_alp_demuxer = {
    .p.name         = "alp",
    .p.long_name    = NULL_IF_CONFIG_SMALL("LEGO Racers ALP"),
    .priv_data_size = sizeof(ALPHeader),
    .read_probe     = alp_probe,
    .read_header    = alp_read_header,
    .read_packet    = alp_read_packet,
    .read_seek      = alp_seek,
};
#endif

#if CONFIG_ALP_MUXER

static int alp_write_init(AVFormatContext *s)
{
    ALPMuxContext *alp = s->priv_data;
    AVCodecParameters *par;

    if (alp->type == ALP_TYPE_AUTO) {
        if (av_match_ext(s->url, "pcm"))
            alp->type = ALP_TYPE_PCM;
        else
            alp->type = ALP_TYPE_TUN;
    }

    par = s->streams[0]->codecpar;

    if (par->ch_layout.nb_channels > 2) {
        av_log(s, AV_LOG_ERROR, "A maximum of 2 channels are supported\n");
        return AVERROR(EINVAL);
    }

    if (par->sample_rate > 44100) {
        av_log(s, AV_LOG_ERROR, "Sample rate too large\n");
        return AVERROR(EINVAL);
    }

    if (alp->type == ALP_TYPE_TUN && par->sample_rate != 22050) {
        av_log(s, AV_LOG_ERROR, "Sample rate must be 22050 for TUN files\n");
        return AVERROR(EINVAL);
    }
    return 0;
}

static int alp_write_header(AVFormatContext *s)
{
    ALPMuxContext *alp = s->priv_data;
    AVCodecParameters *par = s->streams[0]->codecpar;

    avio_wl32(s->pb,  ALP_TAG);
    avio_wl32(s->pb,  alp->type == ALP_TYPE_PCM ? 12 : 8);
    avio_write(s->pb, "ADPCM", 6);
    avio_w8(s->pb,    0);
    avio_w8(s->pb,    par->ch_layout.nb_channels);
    if (alp->type == ALP_TYPE_PCM)
        avio_wl32(s->pb, par->sample_rate);

    return 0;
}

enum { AE = AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM };

static const AVOption alp_options[] = {
    {
        .name        = "type",
        .help        = "set file type",
        .offset      = offsetof(ALPMuxContext, type),
        .type        = AV_OPT_TYPE_INT,
        .default_val = {.i64 = ALP_TYPE_AUTO},
        .min         = ALP_TYPE_AUTO,
        .max         = ALP_TYPE_PCM,
        .flags       = AE,
        .unit        = "type",
    },
    {
        .name        = "auto",
        .help        = "autodetect based on file extension",
        .offset      = 0,
        .type        = AV_OPT_TYPE_CONST,
        .default_val = {.i64 = ALP_TYPE_AUTO},
        .min         = 0,
        .max         = 0,
        .flags       = AE,
        .unit        = "type"
    },
    {
        .name        = "tun",
        .help        = "force .tun, used for music",
        .offset      = 0,
        .type        = AV_OPT_TYPE_CONST,
        .default_val = {.i64 = ALP_TYPE_TUN},
        .min         = 0,
        .max         = 0,
        .flags       = AE,
        .unit        = "type"
    },
    {
        .name        = "pcm",
        .help        = "force .pcm, used for sfx",
        .offset      = 0,
        .type        = AV_OPT_TYPE_CONST,
        .default_val = {.i64 = ALP_TYPE_PCM},
        .min         = 0,
        .max         = 0,
        .flags       = AE,
        .unit        = "type"
    },
    { NULL }
};

static const AVClass alp_muxer_class = {
    .class_name = "alp",
    .item_name  = av_default_item_name,
    .option     = alp_options,
    .version    = LIBAVUTIL_VERSION_INT
};

const FFOutputFormat ff_alp_muxer = {
    .p.name         = "alp",
    .p.long_name    = NULL_IF_CONFIG_SMALL("LEGO Racers ALP"),
    .p.extensions   = "tun,pcm",
    .p.audio_codec  = AV_CODEC_ID_ADPCM_IMA_ALP,
    .p.video_codec  = AV_CODEC_ID_NONE,
    .p.subtitle_codec = AV_CODEC_ID_NONE,
    .p.priv_class   = &alp_muxer_class,
    .flags_internal   = FF_OFMT_FLAG_MAX_ONE_OF_EACH |
                        FF_OFMT_FLAG_ONLY_DEFAULT_CODECS,
    .init           = alp_write_init,
    .write_header   = alp_write_header,
    .write_packet   = ff_raw_write_packet,
    .priv_data_size = sizeof(ALPMuxContext)
};
#endif

Coverage Report

Created: 2026-01-16 07:48

Line	Count	Source
1		/*
2		* LEGO Racers ALP (.tun & .pcm) (de)muxer
3		*
4		* Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com)
5		*
6		* This file is part of FFmpeg.
7		*
8		* FFmpeg is free software; you can redistribute it and/or
9		* modify it under the terms of the GNU Lesser General Public
10		* License as published by the Free Software Foundation; either
11		* version 2.1 of the License, or (at your option) any later version.
12		*
13		* FFmpeg is distributed in the hope that it will be useful,
14		* but WITHOUT ANY WARRANTY; without even the implied warranty of
15		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16		* Lesser General Public License for more details.
17		*
18		* You should have received a copy of the GNU Lesser General Public
19		* License along with FFmpeg; if not, write to the Free Software
20		* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21		*/
22
23		#include "config_components.h"
24
25		#include "libavutil/channel_layout.h"
26		#include "avformat.h"
27		#include "avio_internal.h"
28		#include "demux.h"
29		#include "internal.h"
30		#include "mux.h"
31		#include "rawenc.h"
32		#include "libavutil/intreadwrite.h"
33		#include "libavutil/internal.h"
34		#include "libavutil/opt.h"
35
36	959k	#define ALP_TAG MKTAG('A', 'L', 'P', ' ')
37	12.0k	#define ALP_MAX_READ_SIZE 4096
38
39		typedef struct ALPHeader {
40		uint32_t magic; /< Magic Number, {'A', 'L', 'P', ' '} /
41		uint32_t header_size; /< Header size (after this). /
42		char adpcm[6]; /< "ADPCM" /
43		uint8_t unk1; /< Unknown /
44		uint8_t num_channels; /< Channel Count. /
45		uint32_t sample_rate; /< Sample rate, only if header_size >= 12. /
46		} ALPHeader;
47
48		typedef enum ALPType {
49		ALP_TYPE_AUTO = 0, /< Autodetect based on file extension. /
50		ALP_TYPE_TUN = 1, /< Force a .TUN file. /
51		ALP_TYPE_PCM = 2, /< Force a .PCM file. /
52		} ALPType;
53
54		typedef struct ALPMuxContext {
55		const AVClass *class;
56		ALPType type;
57		} ALPMuxContext;
58
59		#if CONFIG_ALP_DEMUXER
60		static int alp_probe(const AVProbeData *p)
61	958k	{
62	958k	uint32_t i;
63
64	958k	if (AV_RL32(p->buf) != ALP_TAG)
65	957k	return 0;
66
67		/* Only allowed header sizes are 8 and 12. */
68	544	i = AV_RL32(p->buf + 4);
69	544	if (i != 8 && i != 12)
70	268	return 0;
71
72	276	if (strncmp("ADPCM", p->buf + 8, 6) != 0)
73	226	return 0;
74
75	50	return AVPROBE_SCORE_MAX - 1;
76	276	}
77
78		static int alp_read_header(AVFormatContext *s)
79	1.24k	{
80	1.24k	int ret;
81	1.24k	AVStream *st;
82	1.24k	ALPHeader *hdr = s->priv_data;
83	1.24k	AVCodecParameters *par;
84
85	1.24k	if ((hdr->magic = avio_rl32(s->pb)) != ALP_TAG)
86	195	return AVERROR_INVALIDDATA;
87
88	1.04k	hdr->header_size = avio_rl32(s->pb);
89
90	1.04k	if (hdr->header_size != 8 && hdr->header_size != 12) {
91	62	return AVERROR_INVALIDDATA;
92	62	}
93
94	984	if ((ret = ffio_read_size(s->pb, hdr->adpcm, sizeof(hdr->adpcm))) < 0)
95	15	return ret;
96
97	969	if (strncmp("ADPCM", hdr->adpcm, sizeof(hdr->adpcm)) != 0)
98	51	return AVERROR_INVALIDDATA;
99
100	918	hdr->unk1 = avio_r8(s->pb);
101	918	hdr->num_channels = avio_r8(s->pb);
102
103	918	if (hdr->header_size == 8) {
104		/* .TUN music file */
105	399	hdr->sample_rate = 22050;
106
107	519	} else {
108		/* .PCM sound file */
109	519	hdr->sample_rate = avio_rl32(s->pb);
110	519	}
111
112	918	if (hdr->sample_rate > 44100) {
113	28	avpriv_request_sample(s, "Sample Rate > 44100");
114	28	return AVERROR_PATCHWELCOME;
115	28	}
116
117	890	if (!(st = avformat_new_stream(s, NULL)))
118	0	return AVERROR(ENOMEM);
119
120	890	par = st->codecpar;
121	890	par->codec_type = AVMEDIA_TYPE_AUDIO;
122	890	par->codec_id = AV_CODEC_ID_ADPCM_IMA_ALP;
123	890	par->format = AV_SAMPLE_FMT_S16;
124	890	par->sample_rate = hdr->sample_rate;
125
126	890	if (hdr->num_channels > 2 \|\| hdr->num_channels == 0)
127	22	return AVERROR_INVALIDDATA;
128
129	868	av_channel_layout_default(&par->ch_layout, hdr->num_channels);
130	868	par->bits_per_coded_sample = 4;
131	868	par->block_align = 1;
132	868	par->bit_rate = par->ch_layout.nb_channels *
133	868	par->sample_rate *
134	868	par->bits_per_coded_sample;
135
136	868	avpriv_set_pts_info(st, 64, 1, par->sample_rate);
137	868	return 0;
138	890	}
139
140		static int alp_read_packet(AVFormatContext s, AVPacket pkt)
141	12.0k	{
142	12.0k	int ret;
143	12.0k	AVCodecParameters *par = s->streams[0]->codecpar;
144
145	12.0k	if ((ret = av_get_packet(s->pb, pkt, ALP_MAX_READ_SIZE)) < 0)
146	1.21k	return ret;
147
148	10.8k	pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
149	10.8k	pkt->stream_index = 0;
150	10.8k	pkt->duration = ret * 2 / par->ch_layout.nb_channels;
151
152	10.8k	return 0;
153	12.0k	}
154
155		static int alp_seek(AVFormatContext *s, int stream_index,
156		int64_t pts, int flags)
157	0	{
158	0	const ALPHeader *hdr = s->priv_data;
159
160	0	if (pts != 0)
161	0	return AVERROR(EINVAL);
162
163	0	return avio_seek(s->pb, hdr->header_size + 8, SEEK_SET);
164	0	}
165
166		const FFInputFormat ff_alp_demuxer = {
167		.p.name = "alp",
168		.p.long_name = NULL_IF_CONFIG_SMALL("LEGO Racers ALP"),
169		.priv_data_size = sizeof(ALPHeader),
170		.read_probe = alp_probe,
171		.read_header = alp_read_header,
172		.read_packet = alp_read_packet,
173		.read_seek = alp_seek,
174		};
175		#endif
176
177		#if CONFIG_ALP_MUXER
178
179		static int alp_write_init(AVFormatContext *s)
180		{
181		ALPMuxContext *alp = s->priv_data;
182		AVCodecParameters *par;
183
184		if (alp->type == ALP_TYPE_AUTO) {
185		if (av_match_ext(s->url, "pcm"))
186		alp->type = ALP_TYPE_PCM;
187		else
188		alp->type = ALP_TYPE_TUN;
189		}
190
191		par = s->streams[0]->codecpar;
192
193		if (par->ch_layout.nb_channels > 2) {
194		av_log(s, AV_LOG_ERROR, "A maximum of 2 channels are supported\n");
195		return AVERROR(EINVAL);
196		}
197
198		if (par->sample_rate > 44100) {
199		av_log(s, AV_LOG_ERROR, "Sample rate too large\n");
200		return AVERROR(EINVAL);
201		}
202
203		if (alp->type == ALP_TYPE_TUN && par->sample_rate != 22050) {
204		av_log(s, AV_LOG_ERROR, "Sample rate must be 22050 for TUN files\n");
205		return AVERROR(EINVAL);
206		}
207		return 0;
208		}
209
210		static int alp_write_header(AVFormatContext *s)
211		{
212		ALPMuxContext *alp = s->priv_data;
213		AVCodecParameters *par = s->streams[0]->codecpar;
214
215		avio_wl32(s->pb, ALP_TAG);
216		avio_wl32(s->pb, alp->type == ALP_TYPE_PCM ? 12 : 8);
217		avio_write(s->pb, "ADPCM", 6);
218		avio_w8(s->pb, 0);
219		avio_w8(s->pb, par->ch_layout.nb_channels);
220		if (alp->type == ALP_TYPE_PCM)
221		avio_wl32(s->pb, par->sample_rate);
222
223		return 0;
224		}
225
226		enum { AE = AV_OPT_FLAG_AUDIO_PARAM \| AV_OPT_FLAG_ENCODING_PARAM };
227
228		static const AVOption alp_options[] = {
229		{
230		.name = "type",
231		.help = "set file type",
232		.offset = offsetof(ALPMuxContext, type),
233		.type = AV_OPT_TYPE_INT,
234		.default_val = {.i64 = ALP_TYPE_AUTO},
235		.min = ALP_TYPE_AUTO,
236		.max = ALP_TYPE_PCM,
237		.flags = AE,
238		.unit = "type",
239		},
240		{
241		.name = "auto",
242		.help = "autodetect based on file extension",
243		.offset = 0,
244		.type = AV_OPT_TYPE_CONST,
245		.default_val = {.i64 = ALP_TYPE_AUTO},
246		.min = 0,
247		.max = 0,
248		.flags = AE,
249		.unit = "type"
250		},
251		{
252		.name = "tun",
253		.help = "force .tun, used for music",
254		.offset = 0,
255		.type = AV_OPT_TYPE_CONST,
256		.default_val = {.i64 = ALP_TYPE_TUN},
257		.min = 0,
258		.max = 0,
259		.flags = AE,
260		.unit = "type"
261		},
262		{
263		.name = "pcm",
264		.help = "force .pcm, used for sfx",
265		.offset = 0,
266		.type = AV_OPT_TYPE_CONST,
267		.default_val = {.i64 = ALP_TYPE_PCM},
268		.min = 0,
269		.max = 0,
270		.flags = AE,
271		.unit = "type"
272		},
273		{ NULL }
274		};
275
276		static const AVClass alp_muxer_class = {
277		.class_name = "alp",
278		.item_name = av_default_item_name,
279		.option = alp_options,
280		.version = LIBAVUTIL_VERSION_INT
281		};
282
283		const FFOutputFormat ff_alp_muxer = {
284		.p.name = "alp",
285		.p.long_name = NULL_IF_CONFIG_SMALL("LEGO Racers ALP"),
286		.p.extensions = "tun,pcm",
287		.p.audio_codec = AV_CODEC_ID_ADPCM_IMA_ALP,
288		.p.video_codec = AV_CODEC_ID_NONE,
289		.p.subtitle_codec = AV_CODEC_ID_NONE,
290		.p.priv_class = &alp_muxer_class,
291		.flags_internal = FF_OFMT_FLAG_MAX_ONE_OF_EACH \|
292		FF_OFMT_FLAG_ONLY_DEFAULT_CODECS,
293		.init = alp_write_init,
294		.write_header = alp_write_header,
295		.write_packet = ff_raw_write_packet,
296		.priv_data_size = sizeof(ALPMuxContext)
297		};
298		#endif