2 * Rayman 2 APM (De)muxer
4 * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com)
6 * This file is part of FFmpeg.
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.
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.
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
25 #include "libavutil/avassert.h"
26 #include "libavutil/internal.h"
27 #include "libavutil/intreadwrite.h"
29 #define APM_FILE_HEADER_SIZE 20
30 #define APM_FILE_EXTRADATA_SIZE 80
31 #define APM_EXTRADATA_SIZE 28
33 #define APM_MAX_READ_SIZE 4096
35 #define APM_TAG_CODEC 0x2000
36 #define APM_TAG_VS12 MKTAG('v', 's', '1', '2')
37 #define APM_TAG_DATA MKTAG('D', 'A', 'T', 'A')
39 typedef struct APMState {
49 typedef struct APMExtraData {
60 #if CONFIG_APM_DEMUXER
61 static void apm_parse_extradata(APMExtraData *ext, const uint8_t *buf)
63 ext->magic = AV_RL32(buf + 0);
64 ext->file_size = AV_RL32(buf + 4);
65 ext->data_size = AV_RL32(buf + 8);
66 ext->unk1 = AV_RL32(buf + 12);
67 ext->unk2 = AV_RL32(buf + 16);
69 ext->state.has_saved = AV_RL32(buf + 20);
70 ext->state.predictor_r = AV_RL32(buf + 24);
71 ext->state.step_index_r = AV_RL32(buf + 28);
72 ext->state.saved_r = AV_RL32(buf + 32);
73 ext->state.predictor_l = AV_RL32(buf + 36);
74 ext->state.step_index_l = AV_RL32(buf + 40);
75 ext->state.saved_l = AV_RL32(buf + 44);
77 for (int i = 0; i < FF_ARRAY_ELEMS(ext->unk3); i++)
78 ext->unk3[i] = AV_RL32(buf + 48 + (i * 4));
80 ext->data = AV_RL32(buf + 76);
83 static int apm_probe(const AVProbeData *p)
85 if (AV_RL16(p->buf) != APM_TAG_CODEC)
88 if (p->buf_size < 100)
91 if (AV_RL32(p->buf + 20) != APM_TAG_VS12)
94 if (AV_RL32(p->buf + 96) != APM_TAG_DATA)
97 return AVPROBE_SCORE_MAX - 1;
100 static int apm_read_header(AVFormatContext *s)
104 APMExtraData extradata;
105 AVCodecParameters *par;
106 uint8_t buf[APM_FILE_EXTRADATA_SIZE];
108 if (!(st = avformat_new_stream(s, NULL)))
109 return AVERROR(ENOMEM);
112 * This is 98% a WAVEFORMATEX, but there's something screwy with the extradata
113 * that ff_get_wav_header() can't (and shouldn't) handle properly.
115 if (avio_rl16(s->pb) != APM_TAG_CODEC)
116 return AVERROR_INVALIDDATA;
119 par->channels = avio_rl16(s->pb);
120 par->sample_rate = avio_rl32(s->pb);
122 /* Skip the bitrate, it's usually wrong anyway. */
123 if ((ret = avio_skip(s->pb, 4)) < 0)
126 par->block_align = avio_rl16(s->pb);
127 par->bits_per_coded_sample = avio_rl16(s->pb);
129 if (avio_rl32(s->pb) != APM_FILE_EXTRADATA_SIZE)
130 return AVERROR_INVALIDDATA;
132 /* 8 = bits per sample * max channels */
133 if (par->sample_rate > (INT_MAX / 8))
134 return AVERROR_INVALIDDATA;
136 if (par->bits_per_coded_sample != 4)
137 return AVERROR_INVALIDDATA;
139 if (par->channels == 2)
140 par->channel_layout = AV_CH_LAYOUT_STEREO;
141 else if (par->channels == 1)
142 par->channel_layout = AV_CH_LAYOUT_MONO;
144 return AVERROR_INVALIDDATA;
146 par->codec_type = AVMEDIA_TYPE_AUDIO;
147 par->codec_id = AV_CODEC_ID_ADPCM_IMA_APM;
148 par->format = AV_SAMPLE_FMT_S16;
149 par->bits_per_raw_sample = 16;
150 par->bit_rate = par->channels *
152 par->bits_per_coded_sample;
154 if ((ret = avio_read(s->pb, buf, APM_FILE_EXTRADATA_SIZE)) < 0)
156 else if (ret != APM_FILE_EXTRADATA_SIZE)
159 apm_parse_extradata(&extradata, buf);
161 if (extradata.magic != APM_TAG_VS12 || extradata.data != APM_TAG_DATA)
162 return AVERROR_INVALIDDATA;
164 if (extradata.state.has_saved) {
165 avpriv_request_sample(s, "Saved Samples");
166 return AVERROR_PATCHWELCOME;
169 if ((ret = ff_alloc_extradata(par, APM_EXTRADATA_SIZE)) < 0)
172 /* Use the entire state as extradata. */
173 memcpy(par->extradata, buf + 20, APM_EXTRADATA_SIZE);
175 avpriv_set_pts_info(st, 64, 1, par->sample_rate);
177 st->duration = extradata.data_size *
178 (8 / par->bits_per_coded_sample) /
183 static int apm_read_packet(AVFormatContext *s, AVPacket *pkt)
186 AVCodecParameters *par = s->streams[0]->codecpar;
189 * For future reference: if files with the `has_saved` field set ever
190 * surface, `saved_l`, and `saved_r` will each contain 8 "saved" samples
191 * that should be sent to the decoder before the actual data.
194 if ((ret = av_get_packet(s->pb, pkt, APM_MAX_READ_SIZE)) < 0)
197 pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
198 pkt->stream_index = 0;
199 pkt->duration = ret * (8 / par->bits_per_coded_sample) / par->channels;
204 AVInputFormat ff_apm_demuxer = {
206 .long_name = NULL_IF_CONFIG_SMALL("Ubisoft Rayman 2 APM"),
207 .read_probe = apm_probe,
208 .read_header = apm_read_header,
209 .read_packet = apm_read_packet
214 static int apm_write_init(AVFormatContext *s)
216 AVCodecParameters *par;
218 if (s->nb_streams != 1) {
219 av_log(s, AV_LOG_ERROR, "APM files have exactly one stream\n");
220 return AVERROR(EINVAL);
223 par = s->streams[0]->codecpar;
225 if (par->codec_id != AV_CODEC_ID_ADPCM_IMA_APM) {
226 av_log(s, AV_LOG_ERROR, "%s codec not supported\n",
227 avcodec_get_name(par->codec_id));
228 return AVERROR(EINVAL);
231 if (par->channels > 2) {
232 av_log(s, AV_LOG_ERROR, "APM files only support up to 2 channels\n");
233 return AVERROR(EINVAL);
236 if (par->sample_rate > (INT_MAX / 8)) {
237 av_log(s, AV_LOG_ERROR, "Sample rate too large\n");
238 return AVERROR(EINVAL);
241 if (par->extradata_size != APM_EXTRADATA_SIZE) {
242 av_log(s, AV_LOG_ERROR, "Invalid/missing extradata\n");
243 return AVERROR(EINVAL);
246 if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL)) {
247 av_log(s, AV_LOG_ERROR, "Stream not seekable, unable to write output file\n");
248 return AVERROR(EINVAL);
254 static int apm_write_header(AVFormatContext *s)
256 uint8_t buf[APM_FILE_EXTRADATA_SIZE] = { 0 };
257 AVCodecParameters *par = s->streams[0]->codecpar;
260 * Bodge a WAVEFORMATEX manually, ff_put_wav_header() can't
261 * be used because of the extra 2 bytes.
263 avio_wl16(s->pb, APM_TAG_CODEC);
264 avio_wl16(s->pb, par->channels);
265 avio_wl32(s->pb, par->sample_rate);
266 /* This is the wrong calculation, but it's what the orginal files have. */
267 avio_wl32(s->pb, par->sample_rate * par->channels * 2);
268 avio_wl16(s->pb, par->block_align);
269 avio_wl16(s->pb, par->bits_per_coded_sample);
270 avio_wl32(s->pb, APM_FILE_EXTRADATA_SIZE);
273 * Build the extradata. Assume the codec's given us correct data.
274 * File and data sizes are fixed later.
276 AV_WL32(buf + 0, APM_TAG_VS12); /* magic */
277 AV_WL32(buf + 12, 0xFFFFFFFF); /* unk1 */
278 memcpy( buf + 20, par->extradata, APM_EXTRADATA_SIZE);
279 AV_WL32(buf + 76, APM_TAG_DATA); /* data */
281 avio_write(s->pb, buf, APM_FILE_EXTRADATA_SIZE);
285 static int apm_write_trailer(AVFormatContext *s)
287 int64_t file_size, data_size;
289 file_size = avio_tell(s->pb);
290 data_size = file_size - (APM_FILE_HEADER_SIZE + APM_FILE_EXTRADATA_SIZE);
292 if (file_size >= UINT32_MAX) {
293 av_log(s, AV_LOG_ERROR,
294 "Filesize %"PRId64" invalid for APM, output file will be broken\n",
296 return AVERROR(ERANGE);
299 avio_seek(s->pb, 24, SEEK_SET);
300 avio_wl32(s->pb, (uint32_t)file_size);
301 avio_wl32(s->pb, (uint32_t)data_size);
306 AVOutputFormat ff_apm_muxer = {
308 .long_name = NULL_IF_CONFIG_SMALL("Ubisoft Rayman 2 APM"),
310 .audio_codec = AV_CODEC_ID_ADPCM_IMA_APM,
311 .video_codec = AV_CODEC_ID_NONE,
312 .init = apm_write_init,
313 .write_header = apm_write_header,
314 .write_packet = ff_raw_write_packet,
315 .write_trailer = apm_write_trailer