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1 /*
2  * 4X Technologies .4xm File Demuxer (no muxer)
3  * Copyright (c) 2003  The FFmpeg project
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * 4X Technologies file demuxer
25  * by Mike Melanson (melanson@pcisys.net)
26  * for more information on the .4xm file format, visit:
27  *   http://www.pcisys.net/~melanson/codecs/
28  */
29 
30 #include "libavutil/intreadwrite.h"
31 #include "libavutil/intfloat.h"
32 #include "libavcodec/internal.h"
33 #include "avformat.h"
34 #include "internal.h"
35 
36 #define     RIFF_TAG MKTAG('R', 'I', 'F', 'F')
37 #define  FOURXMV_TAG MKTAG('4', 'X', 'M', 'V')
38 #define     LIST_TAG MKTAG('L', 'I', 'S', 'T')
39 #define     HEAD_TAG MKTAG('H', 'E', 'A', 'D')
40 #define     TRK__TAG MKTAG('T', 'R', 'K', '_')
41 #define     MOVI_TAG MKTAG('M', 'O', 'V', 'I')
42 #define     VTRK_TAG MKTAG('V', 'T', 'R', 'K')
43 #define     STRK_TAG MKTAG('S', 'T', 'R', 'K')
44 #define     std__TAG MKTAG('s', 't', 'd', '_')
45 #define     name_TAG MKTAG('n', 'a', 'm', 'e')
46 #define     vtrk_TAG MKTAG('v', 't', 'r', 'k')
47 #define     strk_TAG MKTAG('s', 't', 'r', 'k')
48 #define     ifrm_TAG MKTAG('i', 'f', 'r', 'm')
49 #define     pfrm_TAG MKTAG('p', 'f', 'r', 'm')
50 #define     cfrm_TAG MKTAG('c', 'f', 'r', 'm')
51 #define     ifr2_TAG MKTAG('i', 'f', 'r', '2')
52 #define     pfr2_TAG MKTAG('p', 'f', 'r', '2')
53 #define     cfr2_TAG MKTAG('c', 'f', 'r', '2')
54 #define     snd__TAG MKTAG('s', 'n', 'd', '_')
55 
56 #define vtrk_SIZE 0x44
57 #define strk_SIZE 0x28
58 
59 #define GET_LIST_HEADER() \
60     fourcc_tag = avio_rl32(pb); \
61     size       = avio_rl32(pb); \
62     if (fourcc_tag != LIST_TAG) { \
63         ret = AVERROR_INVALIDDATA; \
64         goto fail; \
65     } \
66     fourcc_tag = avio_rl32(pb);
67 
68 typedef struct AudioTrack {
69     int sample_rate;
70     int bits;
71     int channels;
72     int stream_index;
73     int adpcm;
74     int64_t audio_pts;
75 } AudioTrack;
76 
77 typedef struct FourxmDemuxContext {
78     int video_stream_index;
79     int track_count;
80     AudioTrack *tracks;
81 
82     int64_t video_pts;
83     AVRational fps;
84 } FourxmDemuxContext;
85 
fourxm_probe(const AVProbeData * p)86 static int fourxm_probe(const AVProbeData *p)
87 {
88     if ((AV_RL32(&p->buf[0]) != RIFF_TAG) ||
89         (AV_RL32(&p->buf[8]) != FOURXMV_TAG))
90         return 0;
91 
92     return AVPROBE_SCORE_MAX;
93 }
94 
parse_vtrk(AVFormatContext * s,FourxmDemuxContext * fourxm,uint8_t * buf,int size,int left)95 static int parse_vtrk(AVFormatContext *s,
96                       FourxmDemuxContext *fourxm, uint8_t *buf, int size,
97                       int left)
98 {
99     AVStream *st;
100     /* check that there is enough data */
101     if (size != vtrk_SIZE || left < size + 8) {
102         return AVERROR_INVALIDDATA;
103     }
104 
105     /* allocate a new AVStream */
106     st = avformat_new_stream(s, NULL);
107     if (!st)
108         return AVERROR(ENOMEM);
109 
110     avpriv_set_pts_info(st, 60, fourxm->fps.den, fourxm->fps.num);
111 
112     fourxm->video_stream_index = st->index;
113 
114     st->codecpar->codec_type     = AVMEDIA_TYPE_VIDEO;
115     st->codecpar->codec_id       = AV_CODEC_ID_4XM;
116 
117     st->codecpar->extradata      = av_mallocz(4 + AV_INPUT_BUFFER_PADDING_SIZE);
118     if (!st->codecpar->extradata)
119         return AVERROR(ENOMEM);
120     st->codecpar->extradata_size = 4;
121     AV_WL32(st->codecpar->extradata, AV_RL32(buf + 16));
122     st->codecpar->width  = AV_RL32(buf + 36);
123     st->codecpar->height = AV_RL32(buf + 40);
124 
125     return 0;
126 }
127 
128 
parse_strk(AVFormatContext * s,FourxmDemuxContext * fourxm,uint8_t * buf,int size,int left)129 static int parse_strk(AVFormatContext *s,
130                       FourxmDemuxContext *fourxm, uint8_t *buf, int size,
131                       int left)
132 {
133     AVStream *st;
134     int track;
135     /* check that there is enough data */
136     if (size != strk_SIZE || left < size + 8)
137         return AVERROR_INVALIDDATA;
138 
139     track = AV_RL32(buf + 8);
140     if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1 ||
141         track >= s->max_streams) {
142         av_log(s, AV_LOG_ERROR, "current_track too large\n");
143         return AVERROR_INVALIDDATA;
144     }
145 
146     if (track + 1 > fourxm->track_count) {
147         if (av_reallocp_array(&fourxm->tracks, track + 1, sizeof(AudioTrack)))
148             return AVERROR(ENOMEM);
149         memset(&fourxm->tracks[fourxm->track_count], 0,
150                sizeof(AudioTrack) * (track + 1 - fourxm->track_count));
151         fourxm->track_count = track + 1;
152     } else {
153         if (fourxm->tracks[track].bits)
154             return AVERROR_INVALIDDATA;
155     }
156     fourxm->tracks[track].adpcm       = AV_RL32(buf + 12);
157     fourxm->tracks[track].channels    = AV_RL32(buf + 36);
158     fourxm->tracks[track].sample_rate = AV_RL32(buf + 40);
159     fourxm->tracks[track].bits        = AV_RL32(buf + 44);
160     fourxm->tracks[track].audio_pts   = 0;
161 
162     if (fourxm->tracks[track].channels    <= 0 ||
163         fourxm->tracks[track].channels     > FF_SANE_NB_CHANNELS ||
164         fourxm->tracks[track].sample_rate <= 0 ||
165         fourxm->tracks[track].bits        <= 0 ||
166         fourxm->tracks[track].bits         > INT_MAX / FF_SANE_NB_CHANNELS) {
167         av_log(s, AV_LOG_ERROR, "audio header invalid\n");
168         return AVERROR_INVALIDDATA;
169     }
170     if (!fourxm->tracks[track].adpcm && fourxm->tracks[track].bits<8) {
171         av_log(s, AV_LOG_ERROR, "bits unspecified for non ADPCM\n");
172         return AVERROR_INVALIDDATA;
173     }
174 
175     if (fourxm->tracks[track].sample_rate > INT64_MAX / fourxm->tracks[track].bits / fourxm->tracks[track].channels) {
176         av_log(s, AV_LOG_ERROR, "Overflow during bit rate calculation %d * %d * %d\n",
177                fourxm->tracks[track].sample_rate, fourxm->tracks[track].bits, fourxm->tracks[track].channels);
178         return AVERROR_INVALIDDATA;
179     }
180 
181     /* allocate a new AVStream */
182     st = avformat_new_stream(s, NULL);
183     if (!st)
184         return AVERROR(ENOMEM);
185 
186     st->id = track;
187     avpriv_set_pts_info(st, 60, 1, fourxm->tracks[track].sample_rate);
188 
189     fourxm->tracks[track].stream_index = st->index;
190 
191     st->codecpar->codec_type            = AVMEDIA_TYPE_AUDIO;
192     st->codecpar->codec_tag             = 0;
193     st->codecpar->ch_layout.nb_channels = fourxm->tracks[track].channels;
194     st->codecpar->sample_rate           = fourxm->tracks[track].sample_rate;
195     st->codecpar->bits_per_coded_sample = fourxm->tracks[track].bits;
196     st->codecpar->bit_rate              = (int64_t)st->codecpar->ch_layout.nb_channels *
197                                           st->codecpar->sample_rate *
198                                           st->codecpar->bits_per_coded_sample;
199     st->codecpar->block_align           = st->codecpar->ch_layout.nb_channels *
200                                           st->codecpar->bits_per_coded_sample;
201 
202     if (fourxm->tracks[track].adpcm){
203         st->codecpar->codec_id = AV_CODEC_ID_ADPCM_4XM;
204     } else if (st->codecpar->bits_per_coded_sample == 8) {
205         st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
206     } else
207         st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE;
208 
209     return 0;
210 }
211 
fourxm_read_header(AVFormatContext * s)212 static int fourxm_read_header(AVFormatContext *s)
213 {
214     AVIOContext *pb = s->pb;
215     unsigned int fourcc_tag;
216     unsigned int size;
217     int header_size;
218     FourxmDemuxContext *fourxm = s->priv_data;
219     unsigned char *header = NULL;
220     int i, ret;
221 
222     fourxm->track_count = 0;
223     fourxm->tracks      = NULL;
224     fourxm->fps         = (AVRational){1,1};
225     fourxm->video_stream_index = -1;
226 
227     /* skip the first 3 32-bit numbers */
228     avio_skip(pb, 12);
229 
230     /* check for LIST-HEAD */
231     GET_LIST_HEADER();
232     header_size = size - 4;
233     if (fourcc_tag != HEAD_TAG || header_size < 0)
234         return AVERROR_INVALIDDATA;
235 
236     /* allocate space for the header and load the whole thing */
237     header = av_malloc(header_size);
238     if (!header)
239         return AVERROR(ENOMEM);
240     if (avio_read(pb, header, header_size) != header_size) {
241         av_free(header);
242         return AVERROR(EIO);
243     }
244 
245     /* take the lazy approach and search for any and all vtrk and strk chunks */
246     for (i = 0; i < header_size - 8; i++) {
247         fourcc_tag = AV_RL32(&header[i]);
248         size       = AV_RL32(&header[i + 4]);
249         if (size > header_size - i - 8 && (fourcc_tag == vtrk_TAG || fourcc_tag == strk_TAG)) {
250             av_log(s, AV_LOG_ERROR, "chunk larger than array %d>%d\n", size, header_size - i - 8);
251             ret = AVERROR_INVALIDDATA;
252             goto fail;
253         }
254 
255         if (fourcc_tag == std__TAG) {
256             if (header_size - i < 16) {
257                 av_log(s, AV_LOG_ERROR, "std TAG truncated\n");
258                 ret = AVERROR_INVALIDDATA;
259                 goto fail;
260             }
261             fourxm->fps = av_d2q(av_int2float(AV_RL32(&header[i + 12])), 10000);
262         } else if (fourcc_tag == vtrk_TAG) {
263             if ((ret = parse_vtrk(s, fourxm, header + i, size,
264                                   header_size - i)) < 0)
265                 goto fail;
266 
267             i += 8 + size;
268         } else if (fourcc_tag == strk_TAG) {
269             if ((ret = parse_strk(s, fourxm, header + i, size,
270                                   header_size - i)) < 0)
271                 goto fail;
272 
273             i += 8 + size;
274         }
275     }
276 
277     /* skip over the LIST-MOVI chunk (which is where the stream should be */
278     GET_LIST_HEADER();
279     if (fourcc_tag != MOVI_TAG) {
280         ret = AVERROR_INVALIDDATA;
281         goto fail;
282     }
283 
284     av_free(header);
285     /* initialize context members */
286     fourxm->video_pts = -1;  /* first frame will push to 0 */
287 
288     return 0;
289 fail:
290     av_free(header);
291     return ret;
292 }
293 
fourxm_read_packet(AVFormatContext * s,AVPacket * pkt)294 static int fourxm_read_packet(AVFormatContext *s,
295                               AVPacket *pkt)
296 {
297     FourxmDemuxContext *fourxm = s->priv_data;
298     AVIOContext *pb            = s->pb;
299     unsigned int fourcc_tag;
300     unsigned int size;
301     int ret = 0;
302     unsigned int track_number;
303     int packet_read = 0;
304     unsigned char header[8];
305     int64_t audio_frame_count;
306 
307     while (!packet_read) {
308         if ((ret = avio_read(s->pb, header, 8)) < 0)
309             return ret;
310         fourcc_tag = AV_RL32(&header[0]);
311         size       = AV_RL32(&header[4]);
312         if (avio_feof(pb))
313             return AVERROR(EIO);
314         switch (fourcc_tag) {
315         case LIST_TAG:
316             /* this is a good time to bump the video pts */
317             fourxm->video_pts++;
318 
319             /* skip the LIST-* tag and move on to the next fourcc */
320             avio_rl32(pb);
321             break;
322 
323         case ifrm_TAG:
324         case pfrm_TAG:
325         case cfrm_TAG:
326         case ifr2_TAG:
327         case pfr2_TAG:
328         case cfr2_TAG:
329             /* allocate 8 more bytes than 'size' to account for fourcc
330              * and size */
331             if (size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE - 8)
332                 return AVERROR_INVALIDDATA;
333             if (fourxm->video_stream_index < 0)
334                 return AVERROR_INVALIDDATA;
335             if ((ret = av_new_packet(pkt, size + 8)) < 0)
336                 return ret;
337             pkt->stream_index = fourxm->video_stream_index;
338             pkt->pts          = fourxm->video_pts;
339             pkt->pos          = avio_tell(s->pb);
340             memcpy(pkt->data, header, 8);
341             ret = avio_read(s->pb, &pkt->data[8], size);
342 
343             if (ret < 0) {
344                 av_packet_unref(pkt);
345             } else {
346                 packet_read = 1;
347                 av_shrink_packet(pkt, ret + 8);
348             }
349             break;
350 
351         case snd__TAG:
352             track_number = avio_rl32(pb);
353             avio_skip(pb, 4);
354             size -= 8;
355 
356             if (track_number < fourxm->track_count &&
357                 fourxm->tracks[track_number].channels > 0) {
358                 ret = av_get_packet(s->pb, pkt, size);
359                 if (ret < 0)
360                     return ret;
361                 pkt->stream_index =
362                     fourxm->tracks[track_number].stream_index;
363                 pkt->pts    = fourxm->tracks[track_number].audio_pts;
364                 packet_read = 1;
365 
366                 /* pts accounting */
367                 audio_frame_count = size;
368                 if (fourxm->tracks[track_number].adpcm)
369                     audio_frame_count -= 2 * (fourxm->tracks[track_number].channels);
370                 audio_frame_count /= fourxm->tracks[track_number].channels;
371                 if (fourxm->tracks[track_number].adpcm) {
372                     audio_frame_count *= 2;
373                 } else
374                     audio_frame_count /=
375                         (fourxm->tracks[track_number].bits / 8);
376                 fourxm->tracks[track_number].audio_pts += audio_frame_count;
377             } else {
378                 avio_skip(pb, size);
379             }
380             break;
381 
382         default:
383             avio_skip(pb, size);
384             break;
385         }
386     }
387     return ret;
388 }
389 
fourxm_read_close(AVFormatContext * s)390 static int fourxm_read_close(AVFormatContext *s)
391 {
392     FourxmDemuxContext *fourxm = s->priv_data;
393 
394     av_freep(&fourxm->tracks);
395 
396     return 0;
397 }
398 
399 const AVInputFormat ff_fourxm_demuxer = {
400     .name           = "4xm",
401     .long_name      = NULL_IF_CONFIG_SMALL("4X Technologies"),
402     .priv_data_size = sizeof(FourxmDemuxContext),
403     .flags_internal = FF_FMT_INIT_CLEANUP,
404     .read_probe     = fourxm_probe,
405     .read_header    = fourxm_read_header,
406     .read_packet    = fourxm_read_packet,
407     .read_close     = fourxm_read_close,
408 };
409