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/internal.h"
26#include "libavutil/intreadwrite.h"
27#include "libavutil/mem.h"
28#include "avcodec.h"
29#include "bytestream.h"
30#include "internal.h"
31
32#define HNM4_CHUNK_ID_PL 19536
33#define HNM4_CHUNK_ID_IZ 23113
34#define HNM4_CHUNK_ID_IU 21833
35#define HNM4_CHUNK_ID_SD 17491
36
37typedef struct Hnm4VideoContext {
38    uint8_t version;
39    int width;
40    int height;
41    uint8_t *current;
42    uint8_t *previous;
43    uint8_t *buffer1;
44    uint8_t *buffer2;
45    uint8_t *processed;
46    uint32_t palette[256];
47} Hnm4VideoContext;
48
49static int getbit(GetByteContext *gb, uint32_t *bitbuf, int *bits)
50{
51    int ret;
52
53    if (!*bits) {
54        *bitbuf = bytestream2_get_le32(gb);
55        *bits = 32;
56    }
57
58    ret = *bitbuf >> 31;
59    *bitbuf <<= 1;
60    (*bits)--;
61
62    return ret;
63}
64
65static void unpack_intraframe(AVCodecContext *avctx, uint8_t *src,
66                              uint32_t size)
67{
68    Hnm4VideoContext *hnm = avctx->priv_data;
69    GetByteContext gb;
70    uint32_t bitbuf = 0, writeoffset = 0, count = 0;
71    uint16_t word;
72    int32_t offset;
73    int bits = 0;
74
75    bytestream2_init(&gb, src, size);
76
77    while (bytestream2_tell(&gb) < size) {
78        if (getbit(&gb, &bitbuf, &bits)) {
79            if (writeoffset >= hnm->width * hnm->height) {
80                av_log(avctx, AV_LOG_ERROR,
81                       "Attempting to write out of bounds\n");
82                break;
83            }
84            hnm->current[writeoffset++] = bytestream2_get_byte(&gb);
85        } else {
86            if (getbit(&gb, &bitbuf, &bits)) {
87                word   = bytestream2_get_le16(&gb);
88                count  = word & 0x07;
89                offset = (word >> 3) - 0x2000;
90                if (!count)
91                    count = bytestream2_get_byte(&gb);
92                if (!count)
93                    return;
94            } else {
95                count  = getbit(&gb, &bitbuf, &bits) * 2;
96                count += getbit(&gb, &bitbuf, &bits);
97                offset = bytestream2_get_byte(&gb) - 0x0100;
98            }
99            count  += 2;
100            offset += writeoffset;
101            if (offset < 0 || offset + count >= hnm->width * hnm->height) {
102                av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
103                break;
104            } else if (writeoffset + count >= hnm->width * hnm->height) {
105                av_log(avctx, AV_LOG_ERROR,
106                       "Attempting to write out of bounds\n");
107                break;
108            }
109            while (count--) {
110                hnm->current[writeoffset++] = hnm->current[offset++];
111            }
112        }
113    }
114}
115
116static void postprocess_current_frame(AVCodecContext *avctx)
117{
118    Hnm4VideoContext *hnm = avctx->priv_data;
119    uint32_t x, y, src_x, src_y;
120
121    for (y = 0; y < hnm->height; y++) {
122        src_y = y - (y % 2);
123        src_x = src_y * hnm->width + (y % 2);
124        for (x = 0; x < hnm->width; x++) {
125            hnm->processed[(y * hnm->width) + x] = hnm->current[src_x];
126            src_x += 2;
127        }
128    }
129}
130
131static void copy_processed_frame(AVCodecContext *avctx, AVFrame *frame)
132{
133    Hnm4VideoContext *hnm = avctx->priv_data;
134    uint8_t *src = hnm->processed;
135    uint8_t *dst = frame->data[0];
136    int y;
137
138    for (y = 0; y < hnm->height; y++) {
139        memcpy(dst, src, hnm->width);
140        src += hnm->width;
141        dst += frame->linesize[0];
142    }
143}
144
145static void decode_interframe_v4(AVCodecContext *avctx, uint8_t *src, uint32_t size)
146{
147    Hnm4VideoContext *hnm = avctx->priv_data;
148    GetByteContext gb;
149    uint32_t writeoffset = 0;
150    int count, left, offset;
151    uint8_t tag, previous, backline, backward, swap;
152
153    bytestream2_init(&gb, src, size);
154
155    while (bytestream2_tell(&gb) < size) {
156        count = bytestream2_peek_byte(&gb) & 0x1F;
157        if (count == 0) {
158            tag = bytestream2_get_byte(&gb) & 0xE0;
159            tag = tag >> 5;
160
161            if (tag == 0) {
162                if (writeoffset + 2 > hnm->width * hnm->height) {
163                    av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
164                    break;
165                }
166                hnm->current[writeoffset++] = bytestream2_get_byte(&gb);
167                hnm->current[writeoffset++] = bytestream2_get_byte(&gb);
168            } else if (tag == 1) {
169                writeoffset += bytestream2_get_byte(&gb) * 2;
170            } else if (tag == 2) {
171                count = bytestream2_get_le16(&gb);
172                count *= 2;
173                writeoffset += count;
174            } else if (tag == 3) {
175                count = bytestream2_get_byte(&gb) * 2;
176                if (writeoffset + count > hnm->width * hnm->height) {
177                    av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
178                    break;
179                }
180                while (count > 0) {
181                    hnm->current[writeoffset++] = bytestream2_peek_byte(&gb);
182                    count--;
183                }
184                bytestream2_skip(&gb, 1);
185            } else {
186                break;
187            }
188            if (writeoffset > hnm->width * hnm->height) {
189                av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
190                break;
191            }
192        } else {
193            previous = bytestream2_peek_byte(&gb) & 0x20;
194            backline = bytestream2_peek_byte(&gb) & 0x40;
195            backward = bytestream2_peek_byte(&gb) & 0x80;
196            bytestream2_skip(&gb, 1);
197            swap   = bytestream2_peek_byte(&gb) & 0x01;
198            offset = bytestream2_get_le16(&gb);
199            offset = (offset >> 1) & 0x7FFF;
200            offset = writeoffset + (offset * 2) - 0x8000;
201
202            left = count;
203
204            if (!backward && offset + 2*count > hnm->width * hnm->height) {
205                av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
206                break;
207            } else if (backward && offset + 1 >= hnm->width * hnm->height) {
208                av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
209                break;
210            } else if (writeoffset + 2*count > hnm->width * hnm->height) {
211                av_log(avctx, AV_LOG_ERROR,
212                       "Attempting to write out of bounds\n");
213                break;
214            }
215            if(backward) {
216                if (offset < (!!backline)*(2 * hnm->width - 1) + 2*(left-1)) {
217                    av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
218                    break;
219                }
220            } else {
221                if (offset < (!!backline)*(2 * hnm->width - 1)) {
222                    av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
223                    break;
224                }
225            }
226
227            if (previous) {
228                while (left > 0) {
229                    if (backline) {
230                        hnm->current[writeoffset++] = hnm->previous[offset - (2 * hnm->width) + 1];
231                        hnm->current[writeoffset++] = hnm->previous[offset++];
232                        offset++;
233                    } else {
234                        hnm->current[writeoffset++] = hnm->previous[offset++];
235                        hnm->current[writeoffset++] = hnm->previous[offset++];
236                    }
237                    if (backward)
238                        offset -= 4;
239                    left--;
240                }
241            } else {
242                while (left > 0) {
243                    if (backline) {
244                        hnm->current[writeoffset++] = hnm->current[offset - (2 * hnm->width) + 1];
245                        hnm->current[writeoffset++] = hnm->current[offset++];
246                        offset++;
247                    } else {
248                        hnm->current[writeoffset++] = hnm->current[offset++];
249                        hnm->current[writeoffset++] = hnm->current[offset++];
250                    }
251                    if (backward)
252                        offset -= 4;
253                    left--;
254                }
255            }
256
257            if (swap) {
258                left         = count;
259                writeoffset -= count * 2;
260                while (left > 0) {
261                    swap = hnm->current[writeoffset];
262                    hnm->current[writeoffset] = hnm->current[writeoffset + 1];
263                    hnm->current[writeoffset + 1] = swap;
264                    left--;
265                    writeoffset += 2;
266                }
267            }
268        }
269    }
270}
271
272static void decode_interframe_v4a(AVCodecContext *avctx, uint8_t *src,
273                                  uint32_t size)
274{
275    Hnm4VideoContext *hnm = avctx->priv_data;
276    GetByteContext gb;
277    uint32_t writeoffset = 0, offset;
278    uint8_t tag, count, previous, delta;
279
280    bytestream2_init(&gb, src, size);
281
282    while (bytestream2_tell(&gb) < size) {
283        count = bytestream2_peek_byte(&gb) & 0x3F;
284        if (count == 0) {
285            tag = bytestream2_get_byte(&gb) & 0xC0;
286            tag = tag >> 6;
287            if (tag == 0) {
288                writeoffset += bytestream2_get_byte(&gb);
289            } else if (tag == 1) {
290                if (writeoffset + hnm->width >= hnm->width * hnm->height) {
291                    av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
292                    break;
293                }
294                hnm->current[writeoffset]              = bytestream2_get_byte(&gb);
295                hnm->current[writeoffset + hnm->width] = bytestream2_get_byte(&gb);
296                writeoffset++;
297            } else if (tag == 2) {
298                writeoffset += hnm->width;
299            } else if (tag == 3) {
300                break;
301            }
302            if (writeoffset > hnm->width * hnm->height) {
303                av_log(avctx, AV_LOG_ERROR, "writeoffset out of bounds\n");
304                break;
305            }
306        } else {
307            delta    = bytestream2_peek_byte(&gb) & 0x80;
308            previous = bytestream2_peek_byte(&gb) & 0x40;
309            bytestream2_skip(&gb, 1);
310
311            offset  = writeoffset;
312            offset += bytestream2_get_le16(&gb);
313
314            if (delta) {
315                if (offset < 0x10000) {
316                    av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
317                    break;
318                }
319                offset -= 0x10000;
320            }
321
322            if (offset + hnm->width + count >= hnm->width * hnm->height) {
323                av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds\n");
324                break;
325            } else if (writeoffset + hnm->width + count >= hnm->width * hnm->height) {
326                av_log(avctx, AV_LOG_ERROR, "Attempting to write out of bounds\n");
327                break;
328            }
329
330            if (previous) {
331                while (count > 0) {
332                    hnm->current[writeoffset]              = hnm->previous[offset];
333                    hnm->current[writeoffset + hnm->width] = hnm->previous[offset + hnm->width];
334                    writeoffset++;
335                    offset++;
336                    count--;
337                }
338            } else {
339                while (count > 0) {
340                    hnm->current[writeoffset]              = hnm->current[offset];
341                    hnm->current[writeoffset + hnm->width] = hnm->current[offset + hnm->width];
342                    writeoffset++;
343                    offset++;
344                    count--;
345                }
346            }
347        }
348    }
349}
350
351static void hnm_update_palette(AVCodecContext *avctx, uint8_t *src,
352                               uint32_t size)
353{
354    Hnm4VideoContext *hnm = avctx->priv_data;
355    GetByteContext gb;
356    uint8_t start, writeoffset;
357    uint16_t count;
358    int eight_bit_colors;
359
360    eight_bit_colors = src[7] & 0x80 && hnm->version == 0x4a;
361
362    // skip first 8 bytes
363    bytestream2_init(&gb, src + 8, size - 8);
364
365    while (bytestream2_tell(&gb) < size - 8) {
366        start = bytestream2_get_byte(&gb);
367        count = bytestream2_get_byte(&gb);
368        if (start == 255 && count == 255)
369            break;
370        if (count == 0)
371            count = 256;
372        writeoffset = start;
373        while (count > 0) {
374            hnm->palette[writeoffset] = bytestream2_get_be24(&gb);
375            if (!eight_bit_colors)
376                hnm->palette[writeoffset] <<= 2;
377            count--;
378            writeoffset++;
379        }
380    }
381}
382
383static void hnm_flip_buffers(Hnm4VideoContext *hnm)
384{
385    uint8_t *temp;
386
387    temp          = hnm->current;
388    hnm->current  = hnm->previous;
389    hnm->previous = temp;
390}
391
392static int hnm_decode_frame(AVCodecContext *avctx, void *data,
393                            int *got_frame, AVPacket *avpkt)
394{
395    AVFrame *frame = data;
396    Hnm4VideoContext *hnm = avctx->priv_data;
397    int ret;
398    uint16_t chunk_id;
399
400    if (avpkt->size < 8) {
401        av_log(avctx, AV_LOG_ERROR, "packet too small\n");
402        return AVERROR_INVALIDDATA;
403    }
404
405    chunk_id = AV_RL16(avpkt->data + 4);
406
407    if (chunk_id == HNM4_CHUNK_ID_PL) {
408        hnm_update_palette(avctx, avpkt->data, avpkt->size);
409    } else if (chunk_id == HNM4_CHUNK_ID_IZ) {
410        if (avpkt->size < 12) {
411            av_log(avctx, AV_LOG_ERROR, "packet too small\n");
412            return AVERROR_INVALIDDATA;
413        }
414        if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
415            return ret;
416
417        unpack_intraframe(avctx, avpkt->data + 12, avpkt->size - 12);
418        memcpy(hnm->previous, hnm->current, hnm->width * hnm->height);
419        if (hnm->version == 0x4a)
420            memcpy(hnm->processed, hnm->current, hnm->width * hnm->height);
421        else
422            postprocess_current_frame(avctx);
423        copy_processed_frame(avctx, frame);
424        frame->pict_type = AV_PICTURE_TYPE_I;
425        frame->key_frame = 1;
426        memcpy(frame->data[1], hnm->palette, 256 * 4);
427        *got_frame = 1;
428    } else if (chunk_id == HNM4_CHUNK_ID_IU) {
429        if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
430            return ret;
431
432        if (hnm->version == 0x4a) {
433            decode_interframe_v4a(avctx, avpkt->data + 8, avpkt->size - 8);
434            memcpy(hnm->processed, hnm->current, hnm->width * hnm->height);
435        } else {
436            decode_interframe_v4(avctx, avpkt->data + 8, avpkt->size - 8);
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        hnm_flip_buffers(hnm);
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
453static av_cold int hnm_decode_init(AVCodecContext *avctx)
454{
455    Hnm4VideoContext *hnm = avctx->priv_data;
456
457    if (avctx->extradata_size < 1) {
458        av_log(avctx, AV_LOG_ERROR,
459               "Extradata missing, decoder requires version number\n");
460        return AVERROR_INVALIDDATA;
461    }
462
463    hnm->version   = avctx->extradata[0];
464    avctx->pix_fmt = AV_PIX_FMT_PAL8;
465    hnm->width     = avctx->width;
466    hnm->height    = avctx->height;
467    hnm->buffer1   = av_mallocz(avctx->width * avctx->height);
468    hnm->buffer2   = av_mallocz(avctx->width * avctx->height);
469    hnm->processed = av_mallocz(avctx->width * avctx->height);
470
471    if (   !hnm->buffer1 || !hnm->buffer2 || !hnm->processed
472        || avctx->width * avctx->height == 0
473        || avctx->height % 2) {
474        av_log(avctx, AV_LOG_ERROR, "av_mallocz() failed\n");
475        av_freep(&hnm->buffer1);
476        av_freep(&hnm->buffer2);
477        av_freep(&hnm->processed);
478        return AVERROR(ENOMEM);
479    }
480
481    hnm->current  = hnm->buffer1;
482    hnm->previous = hnm->buffer2;
483
484    return 0;
485}
486
487static av_cold int hnm_decode_end(AVCodecContext *avctx)
488{
489    Hnm4VideoContext *hnm = avctx->priv_data;
490
491    av_freep(&hnm->buffer1);
492    av_freep(&hnm->buffer2);
493    av_freep(&hnm->processed);
494
495    return 0;
496}
497
498AVCodec ff_hnm4_video_decoder = {
499    .name           = "hnm4video",
500    .long_name      = NULL_IF_CONFIG_SMALL("HNM 4 video"),
501    .type           = AVMEDIA_TYPE_VIDEO,
502    .id             = AV_CODEC_ID_HNM4_VIDEO,
503    .priv_data_size = sizeof(Hnm4VideoContext),
504    .init           = hnm_decode_init,
505    .close          = hnm_decode_end,
506    .decode         = hnm_decode_frame,
507    .capabilities   = CODEC_CAP_DR1,
508};
509