2 * Cryo Interactive Entertainment HNM4 video decoder
4 * Copyright (c) 2012 David Kment
6 * This file is part of Libav.
8 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include "libavutil/imgutils.h"
26 #include "libavutil/internal.h"
27 #include "libavutil/intreadwrite.h"
28 #include "libavutil/mem.h"
30 #include "bytestream.h"
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
38 typedef struct Hnm4VideoContext {
47 uint32_t palette[256];
50 static int getbit(GetByteContext *gb, uint32_t *bitbuf, int *bits)
55 *bitbuf = bytestream2_get_le32(gb);
66 static void unpack_intraframe(AVCodecContext *avctx, uint8_t *src,
69 Hnm4VideoContext *hnm = avctx->priv_data;
71 uint32_t bitbuf = 0, writeoffset = 0, count = 0;
76 bytestream2_init(&gb, src, size);
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");
85 hnm->current[writeoffset++] = bytestream2_get_byte(&gb);
87 if (getbit(&gb, &bitbuf, &bits)) {
88 word = bytestream2_get_le16(&gb);
90 offset = (word >> 3) - 0x2000;
92 count = bytestream2_get_byte(&gb);
96 count = getbit(&gb, &bitbuf, &bits) * 2;
97 count += getbit(&gb, &bitbuf, &bits);
98 offset = bytestream2_get_byte(&gb) - 0x0100;
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");
105 } else if (writeoffset + count >= hnm->width * hnm->height) {
106 av_log(avctx, AV_LOG_ERROR,
107 "Attempting to write out of bounds");
111 hnm->current[writeoffset++] = hnm->current[offset++];
117 static void postprocess_current_frame(AVCodecContext *avctx)
119 Hnm4VideoContext *hnm = avctx->priv_data;
120 uint32_t x, y, src_x, src_y;
122 for (y = 0; y < hnm->height; y++) {
124 src_x = src_y * hnm->width + (y % 2);
125 for (x = 0; x < hnm->width; x++) {
126 hnm->processed[(y * hnm->width) + x] = hnm->current[src_x];
132 static void copy_processed_frame(AVCodecContext *avctx, AVFrame *frame)
134 Hnm4VideoContext *hnm = avctx->priv_data;
135 uint8_t *src = hnm->processed;
136 uint8_t *dst = frame->data[0];
139 for (y = 0; y < hnm->height; y++) {
140 memcpy(dst, src, hnm->width);
142 dst += frame->linesize[0];
146 static void decode_interframe_v4(AVCodecContext *avctx, uint8_t *src, uint32_t size)
148 Hnm4VideoContext *hnm = avctx->priv_data;
150 uint32_t writeoffset = 0, count, left, offset;
151 uint8_t tag, previous, backline, backward, swap;
153 bytestream2_init(&gb, src, size);
155 while (bytestream2_tell(&gb) < size) {
156 count = bytestream2_peek_byte(&gb) & 0x1F;
158 tag = bytestream2_get_byte(&gb) & 0xE0;
161 hnm->current[writeoffset++] = bytestream2_get_byte(&gb);
162 hnm->current[writeoffset++] = bytestream2_get_byte(&gb);
163 } else if (tag == 1) {
164 writeoffset += bytestream2_get_byte(&gb) * 2;
165 } else if (tag == 2) {
166 count = bytestream2_get_le16(&gb);
168 writeoffset += count;
169 } else if (tag == 3) {
170 count = bytestream2_get_byte(&gb) * 2;
172 hnm->current[writeoffset++] = bytestream2_peek_byte(&gb);
175 bytestream2_skip(&gb, 1);
180 previous = bytestream2_peek_byte(&gb) & 0x20;
181 backline = bytestream2_peek_byte(&gb) & 0x40;
182 backward = bytestream2_peek_byte(&gb) & 0x80;
183 bytestream2_skip(&gb, 1);
184 swap = bytestream2_peek_byte(&gb) & 0x01;
185 offset = bytestream2_get_le16(&gb);
186 offset = (offset >> 1) & 0x7FFF;
187 offset = writeoffset + (offset * 2) - 0x8000;
191 if (!backward && offset + count >= hnm->width * hnm->height) {
192 av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds");
194 } else if (backward && offset >= hnm->width * hnm->height) {
195 av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds");
197 } else if (writeoffset + count >= hnm->width * hnm->height) {
198 av_log(avctx, AV_LOG_ERROR,
199 "Attempting to write out of bounds");
206 hnm->current[writeoffset++] = hnm->previous[offset - (2 * hnm->width) + 1];
207 hnm->current[writeoffset++] = hnm->previous[offset++];
210 hnm->current[writeoffset++] = hnm->previous[offset++];
211 hnm->current[writeoffset++] = hnm->previous[offset++];
220 hnm->current[writeoffset++] = hnm->current[offset - (2 * hnm->width) + 1];
221 hnm->current[writeoffset++] = hnm->current[offset++];
224 hnm->current[writeoffset++] = hnm->current[offset++];
225 hnm->current[writeoffset++] = hnm->current[offset++];
235 writeoffset -= count * 2;
237 swap = hnm->current[writeoffset];
238 hnm->current[writeoffset] = hnm->current[writeoffset + 1];
239 hnm->current[writeoffset + 1] = swap;
248 static void decode_interframe_v4a(AVCodecContext *avctx, uint8_t *src,
251 Hnm4VideoContext *hnm = avctx->priv_data;
253 uint32_t writeoffset = 0, offset;
254 uint8_t tag, count, previous, delta;
256 bytestream2_init(&gb, src, size);
258 while (bytestream2_tell(&gb) < size) {
259 count = bytestream2_peek_byte(&gb) & 0x3F;
261 tag = bytestream2_get_byte(&gb) & 0xC0;
264 writeoffset += bytestream2_get_byte(&gb);
265 } else if (tag == 1) {
266 hnm->current[writeoffset] = bytestream2_get_byte(&gb);
267 hnm->current[writeoffset + hnm->width] = bytestream2_get_byte(&gb);
269 } else if (tag == 2) {
270 writeoffset += hnm->width;
271 } else if (tag == 3) {
275 delta = bytestream2_peek_byte(&gb) & 0x80;
276 previous = bytestream2_peek_byte(&gb) & 0x40;
277 bytestream2_skip(&gb, 1);
279 offset = writeoffset;
280 offset += bytestream2_get_le16(&gb);
285 if (offset + hnm->width + count >= hnm->width * hnm->height) {
286 av_log(avctx, AV_LOG_ERROR, "Attempting to read out of bounds");
288 } else if (writeoffset + hnm->width + count >= hnm->width * hnm->height) {
289 av_log(avctx, AV_LOG_ERROR, "Attempting to write out of bounds");
295 hnm->current[writeoffset] = hnm->previous[offset];
296 hnm->current[writeoffset + hnm->width] = hnm->previous[offset + hnm->width];
303 hnm->current[writeoffset] = hnm->current[offset];
304 hnm->current[writeoffset + hnm->width] = hnm->current[offset + hnm->width];
314 static void hnm_update_palette(AVCodecContext *avctx, uint8_t *src,
317 Hnm4VideoContext *hnm = avctx->priv_data;
319 uint8_t start, writeoffset;
321 int eight_bit_colors;
323 eight_bit_colors = src[7] & 0x80 && hnm->version == 0x4a;
325 // skip first 8 bytes
326 bytestream2_init(&gb, src + 8, size - 8);
328 while (bytestream2_tell(&gb) < size - 8) {
329 start = bytestream2_get_byte(&gb);
330 count = bytestream2_get_byte(&gb);
331 if (start == 255 && count == 255)
337 hnm->palette[writeoffset] = bytestream2_get_be24(&gb);
338 if (!eight_bit_colors)
339 hnm->palette[writeoffset] <<= 2;
346 static void hnm_flip_buffers(Hnm4VideoContext *hnm)
351 hnm->current = hnm->previous;
352 hnm->previous = temp;
355 static int hnm_decode_frame(AVCodecContext *avctx, void *data,
356 int *got_frame, AVPacket *avpkt)
358 AVFrame *frame = data;
359 Hnm4VideoContext *hnm = avctx->priv_data;
363 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
364 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
368 chunk_id = AV_RL16(avpkt->data + 4);
370 if (chunk_id == HNM4_CHUNK_ID_PL) {
371 hnm_update_palette(avctx, avpkt->data, avpkt->size);
372 frame->palette_has_changed = 1;
373 } else if (chunk_id == HNM4_CHUNK_ID_IZ) {
374 unpack_intraframe(avctx, avpkt->data + 12, avpkt->size - 12);
375 memcpy(hnm->previous, hnm->current, hnm->width * hnm->height);
376 if (hnm->version == 0x4a)
377 memcpy(hnm->processed, hnm->current, hnm->width * hnm->height);
379 postprocess_current_frame(avctx);
380 copy_processed_frame(avctx, frame);
381 frame->pict_type = AV_PICTURE_TYPE_I;
382 frame->key_frame = 1;
383 memcpy(frame->data[1], hnm->palette, 256 * 4);
385 } else if (chunk_id == HNM4_CHUNK_ID_IU) {
386 if (hnm->version == 0x4a) {
387 decode_interframe_v4a(avctx, avpkt->data + 8, avpkt->size - 8);
388 memcpy(hnm->processed, hnm->current, hnm->width * hnm->height);
390 decode_interframe_v4(avctx, avpkt->data + 8, avpkt->size - 8);
391 postprocess_current_frame(avctx);
393 copy_processed_frame(avctx, frame);
394 frame->pict_type = AV_PICTURE_TYPE_P;
395 frame->key_frame = 0;
396 memcpy(frame->data[1], hnm->palette, 256 * 4);
398 hnm_flip_buffers(hnm);
400 av_log(avctx, AV_LOG_ERROR, "invalid chunk id: %d\n", chunk_id);
401 return AVERROR_INVALIDDATA;
407 static av_cold int hnm_decode_init(AVCodecContext *avctx)
409 Hnm4VideoContext *hnm = avctx->priv_data;
412 if (avctx->extradata_size < 1) {
413 av_log(avctx, AV_LOG_ERROR,
414 "Extradata missing, decoder requires version number\n");
415 return AVERROR_INVALIDDATA;
418 ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
422 hnm->version = avctx->extradata[0];
423 avctx->pix_fmt = AV_PIX_FMT_PAL8;
424 hnm->width = avctx->width;
425 hnm->height = avctx->height;
426 hnm->buffer1 = av_mallocz(avctx->width * avctx->height);
427 hnm->buffer2 = av_mallocz(avctx->width * avctx->height);
428 hnm->processed = av_mallocz(avctx->width * avctx->height);
430 if (!hnm->buffer1 || !hnm->buffer2 || !hnm->processed) {
431 av_log(avctx, AV_LOG_ERROR, "av_mallocz() failed\n");
432 av_freep(&hnm->buffer1);
433 av_freep(&hnm->buffer2);
434 av_freep(&hnm->processed);
435 return AVERROR(ENOMEM);
438 hnm->current = hnm->buffer1;
439 hnm->previous = hnm->buffer2;
444 static av_cold int hnm_decode_end(AVCodecContext *avctx)
446 Hnm4VideoContext *hnm = avctx->priv_data;
448 av_freep(&hnm->buffer1);
449 av_freep(&hnm->buffer2);
450 av_freep(&hnm->processed);
455 AVCodec ff_hnm4_video_decoder = {
457 .long_name = NULL_IF_CONFIG_SMALL("HNM 4 video"),
458 .type = AVMEDIA_TYPE_VIDEO,
459 .id = AV_CODEC_ID_HNM4_VIDEO,
460 .priv_data_size = sizeof(Hnm4VideoContext),
461 .init = hnm_decode_init,
462 .close = hnm_decode_end,
463 .decode = hnm_decode_frame,
464 .capabilities = CODEC_CAP_DR1,