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1 /*
2  * Cryo Interactive Entertainment HNM4 video decoder
3  *
4  * Copyright (c) 2012 David Kment
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 <string.h>
24 
25 #include "libavutil/imgutils.h"
26 #include "libavutil/internal.h"
27 #include "libavutil/intreadwrite.h"
28 #include "libavutil/mem.h"
29 #include "avcodec.h"
30 #include "bytestream.h"
31 #include "internal.h"
32 
33 #define HNM4_CHUNK_ID_PL 19536
34 #define HNM4_CHUNK_ID_IZ 23113
35 #define HNM4_CHUNK_ID_IU 21833
36 #define HNM4_CHUNK_ID_SD 17491
37 
38 typedef struct Hnm4VideoContext {
39     uint8_t version;
40     int width;
41     int height;
42     uint8_t *current;
43     uint8_t *previous;
44     uint8_t *buffer1;
45     uint8_t *buffer2;
46     uint8_t *processed;
47     uint32_t palette[256];
48 } Hnm4VideoContext;
49 
getbit(GetByteContext * gb,uint32_t * bitbuf,int * bits)50 static int getbit(GetByteContext *gb, uint32_t *bitbuf, int *bits)
51 {
52     int ret;
53 
54     if (!*bits) {
55         *bitbuf = bytestream2_get_le32(gb);
56         *bits = 32;
57     }
58 
59     ret = *bitbuf >> 31;
60     *bitbuf <<= 1;
61     (*bits)--;
62 
63     return ret;
64 }
65 
unpack_intraframe(AVCodecContext * avctx,uint8_t * src,uint32_t size)66 static void unpack_intraframe(AVCodecContext *avctx, uint8_t *src,
67                               uint32_t size)
68 {
69     Hnm4VideoContext *hnm = avctx->priv_data;
70     GetByteContext gb;
71     uint32_t bitbuf = 0, writeoffset = 0, count = 0;
72     uint16_t word;
73     int32_t offset;
74     int bits = 0;
75 
76     bytestream2_init(&gb, src, size);
77 
78     while (bytestream2_tell(&gb) < size) {
79         if (getbit(&gb, &bitbuf, &bits)) {
80             if (writeoffset >= hnm->width * hnm->height) {
81                 av_log(avctx, AV_LOG_ERROR,
82                        "Attempting to write out of bounds\n");
83                 break;
84             }
85             hnm->current[writeoffset++] = bytestream2_get_byte(&gb);
86         } else {
87             if (getbit(&gb, &bitbuf, &bits)) {
88                 word   = bytestream2_get_le16(&gb);
89                 count  = word & 0x07;
90                 offset = (word >> 3) - 0x2000;
91                 if (!count)
92                     count = bytestream2_get_byte(&gb);
93                 if (!count)
94                     return;
95             } else {
96                 count  = getbit(&gb, &bitbuf, &bits) * 2;
97                 count += getbit(&gb, &bitbuf, &bits);
98                 offset = bytestream2_get_byte(&gb) - 0x0100;
99             }
100             count  += 2;
101             offset += writeoffset;
102             if (offset < 0 || offset + count >= hnm->width * hnm->height) {
103                 av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
104                 break;
105             } else if (writeoffset + count >= hnm->width * hnm->height) {
106                 av_log(avctx, AV_LOG_ERROR,
107                        "Attempting to write out of bounds\n");
108                 break;
109             }
110             while (count--) {
111                 hnm->current[writeoffset++] = hnm->current[offset++];
112             }
113         }
114     }
115 }
116 
postprocess_current_frame(AVCodecContext * avctx)117 static void postprocess_current_frame(AVCodecContext *avctx)
118 {
119     Hnm4VideoContext *hnm = avctx->priv_data;
120     uint32_t x, y, src_y;
121     int width = hnm->width;
122 
123     for (y = 0; y < hnm->height; y++) {
124         uint8_t *dst = hnm->processed + y * width;
125         const uint8_t *src = hnm->current;
126         src_y = y - (y % 2);
127         src += src_y * width + (y % 2);
128         for (x = 0; x < width; x++) {
129             dst[x] = *src;
130             src += 2;
131         }
132     }
133 }
134 
copy_processed_frame(AVCodecContext * avctx,AVFrame * frame)135 static void copy_processed_frame(AVCodecContext *avctx, AVFrame *frame)
136 {
137     Hnm4VideoContext *hnm = avctx->priv_data;
138     uint8_t *src = hnm->processed;
139     uint8_t *dst = frame->data[0];
140     int y;
141 
142     for (y = 0; y < hnm->height; y++) {
143         memcpy(dst, src, hnm->width);
144         src += hnm->width;
145         dst += frame->linesize[0];
146     }
147 }
148 
decode_interframe_v4(AVCodecContext * avctx,uint8_t * src,uint32_t size)149 static int decode_interframe_v4(AVCodecContext *avctx, uint8_t *src, uint32_t size)
150 {
151     Hnm4VideoContext *hnm = avctx->priv_data;
152     GetByteContext gb;
153     uint32_t writeoffset = 0;
154     int count, left, offset;
155     uint8_t tag, previous, backline, backward, swap;
156 
157     bytestream2_init(&gb, src, size);
158 
159     while (bytestream2_tell(&gb) < size) {
160         count = bytestream2_peek_byte(&gb) & 0x1F;
161         if (count == 0) {
162             tag = bytestream2_get_byte(&gb) & 0xE0;
163             tag = tag >> 5;
164 
165             if (tag == 0) {
166                 if (writeoffset + 2 > hnm->width * hnm->height) {
167                     av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
168                     return AVERROR_INVALIDDATA;
169                 }
170                 hnm->current[writeoffset++] = bytestream2_get_byte(&gb);
171                 hnm->current[writeoffset++] = bytestream2_get_byte(&gb);
172             } else if (tag == 1) {
173                 writeoffset += bytestream2_get_byte(&gb) * 2;
174             } else if (tag == 2) {
175                 count = bytestream2_get_le16(&gb);
176                 count *= 2;
177                 writeoffset += count;
178             } else if (tag == 3) {
179                 count = bytestream2_get_byte(&gb) * 2;
180                 if (writeoffset + count > hnm->width * hnm->height) {
181                     av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
182                     return AVERROR_INVALIDDATA;
183                 }
184                 while (count > 0) {
185                     hnm->current[writeoffset++] = bytestream2_peek_byte(&gb);
186                     count--;
187                 }
188                 bytestream2_skip(&gb, 1);
189             } else {
190                 break;
191             }
192             if (writeoffset > hnm->width * hnm->height) {
193                 av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
194                 return AVERROR_INVALIDDATA;
195             }
196         } else {
197             previous = bytestream2_peek_byte(&gb) & 0x20;
198             backline = bytestream2_peek_byte(&gb) & 0x40;
199             backward = bytestream2_peek_byte(&gb) & 0x80;
200             bytestream2_skip(&gb, 1);
201             swap   = bytestream2_peek_byte(&gb) & 0x01;
202             offset = bytestream2_get_le16(&gb);
203             offset = (offset >> 1) & 0x7FFF;
204             offset = writeoffset + (offset * 2) - 0x8000;
205 
206             left = count;
207 
208             if (!backward && offset + 2*count > hnm->width * hnm->height) {
209                 av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
210                 return AVERROR_INVALIDDATA;
211             } else if (backward && offset + 1 >= hnm->width * hnm->height) {
212                 av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
213                 return AVERROR_INVALIDDATA;
214             } else if (writeoffset + 2*count > hnm->width * hnm->height) {
215                 av_log(avctx, AV_LOG_ERROR,
216                        "Attempting to write out of bounds\n");
217                 return AVERROR_INVALIDDATA;
218 
219             }
220             if(backward) {
221                 if (offset < (!!backline)*(2 * hnm->width - 1) + 2*(left-1)) {
222                     av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
223                     return AVERROR_INVALIDDATA;
224                 }
225             } else {
226                 if (offset < (!!backline)*(2 * hnm->width - 1)) {
227                     av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
228                     return AVERROR_INVALIDDATA;
229                 }
230             }
231 
232             if (previous) {
233                 while (left > 0) {
234                     if (backline) {
235                         hnm->current[writeoffset++] = hnm->previous[offset - (2 * hnm->width) + 1];
236                         hnm->current[writeoffset++] = hnm->previous[offset++];
237                         offset++;
238                     } else {
239                         hnm->current[writeoffset++] = hnm->previous[offset++];
240                         hnm->current[writeoffset++] = hnm->previous[offset++];
241                     }
242                     if (backward)
243                         offset -= 4;
244                     left--;
245                 }
246             } else {
247                 while (left > 0) {
248                     if (backline) {
249                         hnm->current[writeoffset++] = hnm->current[offset - (2 * hnm->width) + 1];
250                         hnm->current[writeoffset++] = hnm->current[offset++];
251                         offset++;
252                     } else {
253                         hnm->current[writeoffset++] = hnm->current[offset++];
254                         hnm->current[writeoffset++] = hnm->current[offset++];
255                     }
256                     if (backward)
257                         offset -= 4;
258                     left--;
259                 }
260             }
261 
262             if (swap) {
263                 left         = count;
264                 writeoffset -= count * 2;
265                 while (left > 0) {
266                     swap = hnm->current[writeoffset];
267                     hnm->current[writeoffset] = hnm->current[writeoffset + 1];
268                     hnm->current[writeoffset + 1] = swap;
269                     left--;
270                     writeoffset += 2;
271                 }
272             }
273         }
274     }
275     return 0;
276 }
277 
decode_interframe_v4a(AVCodecContext * avctx,uint8_t * src,uint32_t size)278 static void decode_interframe_v4a(AVCodecContext *avctx, uint8_t *src,
279                                   uint32_t size)
280 {
281     Hnm4VideoContext *hnm = avctx->priv_data;
282     GetByteContext gb;
283     uint32_t writeoffset = 0, offset;
284     uint8_t tag, count, previous, delta;
285 
286     bytestream2_init(&gb, src, size);
287 
288     while (bytestream2_tell(&gb) < size) {
289         count = bytestream2_peek_byte(&gb) & 0x3F;
290         if (count == 0) {
291             tag = bytestream2_get_byte(&gb) & 0xC0;
292             tag = tag >> 6;
293             if (tag == 0) {
294                 writeoffset += bytestream2_get_byte(&gb);
295             } else if (tag == 1) {
296                 if (writeoffset + hnm->width >= hnm->width * hnm->height) {
297                     av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
298                     break;
299                 }
300                 hnm->current[writeoffset]              = bytestream2_get_byte(&gb);
301                 hnm->current[writeoffset + hnm->width] = bytestream2_get_byte(&gb);
302                 writeoffset++;
303             } else if (tag == 2) {
304                 writeoffset += hnm->width;
305             } else if (tag == 3) {
306                 break;
307             }
308             if (writeoffset > hnm->width * hnm->height) {
309                 av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
310                 break;
311             }
312         } else {
313             delta    = bytestream2_peek_byte(&gb) & 0x80;
314             previous = bytestream2_peek_byte(&gb) & 0x40;
315             bytestream2_skip(&gb, 1);
316 
317             offset  = writeoffset;
318             offset += bytestream2_get_le16(&gb);
319 
320             if (delta) {
321                 if (offset < 0x10000) {
322                     av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
323                     break;
324                 }
325                 offset -= 0x10000;
326             }
327 
328             if (offset + hnm->width + count >= hnm->width * hnm->height) {
329                 av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
330                 break;
331             } else if (writeoffset + hnm->width + count >= hnm->width * hnm->height) {
332                 av_log(avctx, AV_LOG_ERROR, "Attempting to write out of bounds\n");
333                 break;
334             }
335 
336             if (previous) {
337                 while (count > 0) {
338                     hnm->current[writeoffset]              = hnm->previous[offset];
339                     hnm->current[writeoffset + hnm->width] = hnm->previous[offset + hnm->width];
340                     writeoffset++;
341                     offset++;
342                     count--;
343                 }
344             } else {
345                 while (count > 0) {
346                     hnm->current[writeoffset]              = hnm->current[offset];
347                     hnm->current[writeoffset + hnm->width] = hnm->current[offset + hnm->width];
348                     writeoffset++;
349                     offset++;
350                     count--;
351                 }
352             }
353         }
354     }
355 }
356 
hnm_update_palette(AVCodecContext * avctx,uint8_t * src,uint32_t size)357 static void hnm_update_palette(AVCodecContext *avctx, uint8_t *src,
358                                uint32_t size)
359 {
360     Hnm4VideoContext *hnm = avctx->priv_data;
361     GetByteContext gb;
362     uint8_t start, writeoffset;
363     uint16_t count;
364     int eight_bit_colors;
365 
366     eight_bit_colors = src[7] & 0x80 && hnm->version == 0x4a;
367 
368     // skip first 8 bytes
369     bytestream2_init(&gb, src + 8, size - 8);
370 
371     while (bytestream2_tell(&gb) < size - 8) {
372         start = bytestream2_get_byte(&gb);
373         count = bytestream2_get_byte(&gb);
374         if (start == 255 && count == 255)
375             break;
376         if (count == 0)
377             count = 256;
378         writeoffset = start;
379         while (count > 0) {
380             hnm->palette[writeoffset] = bytestream2_get_be24(&gb);
381             if (!eight_bit_colors)
382                 hnm->palette[writeoffset] <<= 2;
383             hnm->palette[writeoffset] |= (0xFFU << 24);
384             count--;
385             writeoffset++;
386         }
387     }
388 }
389 
hnm_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)390 static int hnm_decode_frame(AVCodecContext *avctx, void *data,
391                             int *got_frame, AVPacket *avpkt)
392 {
393     AVFrame *frame = data;
394     Hnm4VideoContext *hnm = avctx->priv_data;
395     int ret;
396     uint16_t chunk_id;
397 
398     if (avpkt->size < 8) {
399         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
400         return AVERROR_INVALIDDATA;
401     }
402 
403     chunk_id = AV_RL16(avpkt->data + 4);
404 
405     if (chunk_id == HNM4_CHUNK_ID_PL) {
406         hnm_update_palette(avctx, avpkt->data, avpkt->size);
407     } else if (chunk_id == HNM4_CHUNK_ID_IZ) {
408         if (avpkt->size < 12) {
409             av_log(avctx, AV_LOG_ERROR, "packet too small\n");
410             return AVERROR_INVALIDDATA;
411         }
412         if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
413             return ret;
414 
415         unpack_intraframe(avctx, avpkt->data + 12, avpkt->size - 12);
416         memcpy(hnm->previous, hnm->current, hnm->width * hnm->height);
417         if (hnm->version == 0x4a)
418             memcpy(hnm->processed, hnm->current, hnm->width * hnm->height);
419         else
420             postprocess_current_frame(avctx);
421         copy_processed_frame(avctx, frame);
422         frame->pict_type = AV_PICTURE_TYPE_I;
423         frame->key_frame = 1;
424         memcpy(frame->data[1], hnm->palette, 256 * 4);
425         *got_frame = 1;
426     } else if (chunk_id == HNM4_CHUNK_ID_IU) {
427         if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
428             return ret;
429 
430         if (hnm->version == 0x4a) {
431             decode_interframe_v4a(avctx, avpkt->data + 8, avpkt->size - 8);
432             memcpy(hnm->processed, hnm->current, hnm->width * hnm->height);
433         } else {
434             int ret = decode_interframe_v4(avctx, avpkt->data + 8, avpkt->size - 8);
435             if (ret < 0)
436                 return ret;
437             postprocess_current_frame(avctx);
438         }
439         copy_processed_frame(avctx, frame);
440         frame->pict_type = AV_PICTURE_TYPE_P;
441         frame->key_frame = 0;
442         memcpy(frame->data[1], hnm->palette, 256 * 4);
443         *got_frame = 1;
444         FFSWAP(uint8_t *, hnm->current, hnm->previous);
445     } else {
446         av_log(avctx, AV_LOG_ERROR, "invalid chunk id: %d\n", chunk_id);
447         return AVERROR_INVALIDDATA;
448     }
449 
450     return avpkt->size;
451 }
452 
hnm_decode_init(AVCodecContext * avctx)453 static av_cold int hnm_decode_init(AVCodecContext *avctx)
454 {
455     Hnm4VideoContext *hnm = avctx->priv_data;
456     int ret;
457 
458     if (avctx->extradata_size < 1) {
459         av_log(avctx, AV_LOG_ERROR,
460                "Extradata missing, decoder requires version number\n");
461         return AVERROR_INVALIDDATA;
462     }
463 
464     ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
465     if (ret < 0)
466         return ret;
467     if (avctx->height & 1)
468         return AVERROR(EINVAL);
469 
470     hnm->version   = avctx->extradata[0];
471     avctx->pix_fmt = AV_PIX_FMT_PAL8;
472     hnm->width     = avctx->width;
473     hnm->height    = avctx->height;
474     hnm->buffer1   = av_mallocz(avctx->width * avctx->height);
475     hnm->buffer2   = av_mallocz(avctx->width * avctx->height);
476     hnm->processed = av_mallocz(avctx->width * avctx->height);
477 
478     if (!hnm->buffer1 || !hnm->buffer2 || !hnm->processed) {
479         av_log(avctx, AV_LOG_ERROR, "av_mallocz() failed\n");
480         return AVERROR(ENOMEM);
481     }
482 
483     hnm->current  = hnm->buffer1;
484     hnm->previous = hnm->buffer2;
485 
486     return 0;
487 }
488 
hnm_decode_end(AVCodecContext * avctx)489 static av_cold int hnm_decode_end(AVCodecContext *avctx)
490 {
491     Hnm4VideoContext *hnm = avctx->priv_data;
492 
493     av_freep(&hnm->buffer1);
494     av_freep(&hnm->buffer2);
495     av_freep(&hnm->processed);
496 
497     return 0;
498 }
499 
500 AVCodec ff_hnm4_video_decoder = {
501     .name           = "hnm4video",
502     .long_name      = NULL_IF_CONFIG_SMALL("HNM 4 video"),
503     .type           = AVMEDIA_TYPE_VIDEO,
504     .id             = AV_CODEC_ID_HNM4_VIDEO,
505     .priv_data_size = sizeof(Hnm4VideoContext),
506     .init           = hnm_decode_init,
507     .close          = hnm_decode_end,
508     .decode         = hnm_decode_frame,
509     .capabilities   = AV_CODEC_CAP_DR1,
510     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
511 };
512