WebSVN – Kolibri OS – Blame – /contrib/sdk/sources/ffmpeg/ffmpeg-2.8/libavcodec/c93.c

Rev	Author	Line No.	Line
6147	serge	1	/*
		2	* Interplay C93 video decoder
		3	* Copyright (c) 2007 Anssi Hannula
		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	#include "avcodec.h"
		23	#include "bytestream.h"
		24	#include "internal.h"
		25
		26	typedef struct C93DecoderContext {
		27	AVFrame *pictures[2];
		28	int currentpic;
		29	} C93DecoderContext;
		30
		31	typedef enum {
		32	C93_8X8_FROM_PREV = 0x02,
		33	C93_4X4_FROM_PREV = 0x06,
		34	C93_4X4_FROM_CURR = 0x07,
		35	C93_8X8_2COLOR = 0x08,
		36	C93_4X4_2COLOR = 0x0A,
		37	C93_4X4_4COLOR_GRP = 0x0B,
		38	C93_4X4_4COLOR = 0x0D,
		39	C93_NOOP = 0x0E,
		40	C93_8X8_INTRA = 0x0F,
		41	} C93BlockType;
		42
		43	#define WIDTH 320
		44	#define HEIGHT 192
		45
		46	#define C93_HAS_PALETTE 0x01
		47	#define C93_FIRST_FRAME 0x02
		48
		49	static av_cold int decode_end(AVCodecContext *avctx)
		50	{
		51	C93DecoderContext * const c93 = avctx->priv_data;
		52
		53	av_frame_free(&c93->pictures[0]);
		54	av_frame_free(&c93->pictures[1]);
		55
		56	return 0;
		57	}
		58
		59	static av_cold int decode_init(AVCodecContext *avctx)
		60	{
		61	C93DecoderContext *s = avctx->priv_data;
		62	avctx->pix_fmt = AV_PIX_FMT_PAL8;
		63
		64	s->pictures[0] = av_frame_alloc();
		65	s->pictures[1] = av_frame_alloc();
		66	if (!s->pictures[0] \|\| !s->pictures[1]) {
		67	decode_end(avctx);
		68	return AVERROR(ENOMEM);
		69	}
		70
		71	return 0;
		72	}
		73
		74	static inline int copy_block(AVCodecContext avctx, uint8_t to,
		75	uint8_t *from, int offset, int height, int stride)
		76	{
		77	int i;
		78	int width = height;
		79	int from_x = offset % WIDTH;
		80	int from_y = offset / WIDTH;
		81	int overflow = from_x + width - WIDTH;
		82
		83	if (!from) {
		84	/* silently ignoring predictive blocks in first frame */
		85	return 0;
		86	}
		87
		88	if (from_y + height > HEIGHT) {
		89	av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n",
		90	offset);
		91	return AVERROR_INVALIDDATA;
		92	}
		93
		94	if (overflow > 0) {
		95	width -= overflow;
		96	for (i = 0; i < height; i++) {
		97	memcpy(&to[istride+width], &from[(from_y+i)stride], overflow);
		98	}
		99	}
		100
		101	for (i = 0; i < height; i++) {
		102	memcpy(&to[istride], &from[(from_y+i)stride+from_x], width);
		103	}
		104
		105	return 0;
		106	}
		107
		108	static inline void draw_n_color(uint8_t *out, int stride, int width,
		109	int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
		110	{
		111	int x, y;
		112	for (y = 0; y < height; y++) {
		113	if (grps)
		114	cols[0] = grps[3 * (y >> 1)];
		115	for (x = 0; x < width; x++) {
		116	if (grps)
		117	cols[1]= grps[(x >> 1) + 1];
		118	out[x + y*stride] = cols[col & ((1 << bpp) - 1)];
		119	col >>= bpp;
		120	}
		121	}
		122	}
		123
		124	static int decode_frame(AVCodecContext avctx, void data,
		125	int got_frame, AVPacket avpkt)
		126	{
		127	const uint8_t *buf = avpkt->data;
		128	int buf_size = avpkt->size;
		129	C93DecoderContext * const c93 = avctx->priv_data;
		130	AVFrame * const newpic = c93->pictures[c93->currentpic];
		131	AVFrame * const oldpic = c93->pictures[c93->currentpic^1];
		132	GetByteContext gb;
		133	uint8_t *out;
		134	int stride, ret, i, x, y, b, bt = 0;
		135
		136	if ((ret = ff_set_dimensions(avctx, WIDTH, HEIGHT)) < 0)
		137	return ret;
		138
		139	c93->currentpic ^= 1;
		140
		141	if ((ret = ff_reget_buffer(avctx, newpic)) < 0)
		142	return ret;
		143
		144	stride = newpic->linesize[0];
		145
		146	bytestream2_init(&gb, buf, buf_size);
		147	b = bytestream2_get_byte(&gb);
		148	if (b & C93_FIRST_FRAME) {
		149	newpic->pict_type = AV_PICTURE_TYPE_I;
		150	newpic->key_frame = 1;
		151	} else {
		152	newpic->pict_type = AV_PICTURE_TYPE_P;
		153	newpic->key_frame = 0;
		154	}
		155
		156	for (y = 0; y < HEIGHT; y += 8) {
		157	out = newpic->data[0] + y * stride;
		158	for (x = 0; x < WIDTH; x += 8) {
		159	uint8_t *copy_from = oldpic->data[0];
		160	unsigned int offset, j;
		161	uint8_t cols[4], grps[4];
		162	C93BlockType block_type;
		163
		164	if (!bt)
		165	bt = bytestream2_get_byte(&gb);
		166
		167	block_type= bt & 0x0F;
		168	switch (block_type) {
		169	case C93_8X8_FROM_PREV:
		170	offset = bytestream2_get_le16(&gb);
		171	if ((ret = copy_block(avctx, out, copy_from, offset, 8, stride)) < 0)
		172	return ret;
		173	break;
		174
		175	case C93_4X4_FROM_CURR:
		176	copy_from = newpic->data[0];
		177	case C93_4X4_FROM_PREV:
		178	for (j = 0; j < 8; j += 4) {
		179	for (i = 0; i < 8; i += 4) {
		180	int offset = bytestream2_get_le16(&gb);
		181	int from_x = offset % WIDTH;
		182	int from_y = offset / WIDTH;
		183	if (block_type == C93_4X4_FROM_CURR && from_y == y+j &&
		184	(FFABS(from_x - x-i) < 4 \|\| FFABS(from_x - x-i) > WIDTH-4)) {
		185	avpriv_request_sample(avctx, "block overlap %d %d %d %d", from_x, x+i, from_y, y+j);
		186	return AVERROR_INVALIDDATA;
		187	}
		188	if ((ret = copy_block(avctx, &out[j*stride+i],
		189	copy_from, offset, 4, stride)) < 0)
		190	return ret;
		191	}
		192	}
		193	break;
		194
		195	case C93_8X8_2COLOR:
		196	bytestream2_get_buffer(&gb, cols, 2);
		197	for (i = 0; i < 8; i++) {
		198	draw_n_color(out + i*stride, stride, 8, 1, 1, cols,
		199	NULL, bytestream2_get_byte(&gb));
		200	}
		201
		202	break;
		203
		204	case C93_4X4_2COLOR:
		205	case C93_4X4_4COLOR:
		206	case C93_4X4_4COLOR_GRP:
		207	for (j = 0; j < 8; j += 4) {
		208	for (i = 0; i < 8; i += 4) {
		209	if (block_type == C93_4X4_2COLOR) {
		210	bytestream2_get_buffer(&gb, cols, 2);
		211	draw_n_color(out + i + j*stride, stride, 4, 4,
		212	1, cols, NULL, bytestream2_get_le16(&gb));
		213	} else if (block_type == C93_4X4_4COLOR) {
		214	bytestream2_get_buffer(&gb, cols, 4);
		215	draw_n_color(out + i + j*stride, stride, 4, 4,
		216	2, cols, NULL, bytestream2_get_le32(&gb));
		217	} else {
		218	bytestream2_get_buffer(&gb, grps, 4);
		219	draw_n_color(out + i + j*stride, stride, 4, 4,
		220	1, cols, grps, bytestream2_get_le16(&gb));
		221	}
		222	}
		223	}
		224	break;
		225
		226	case C93_NOOP:
		227	break;
		228
		229	case C93_8X8_INTRA:
		230	for (j = 0; j < 8; j++)
		231	bytestream2_get_buffer(&gb, out + j*stride, 8);
		232	break;
		233
		234	default:
		235	av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n",
		236	block_type, x, y);
		237	return AVERROR_INVALIDDATA;
		238	}
		239	bt >>= 4;
		240	out += 8;
		241	}
		242	}
		243
		244	if (b & C93_HAS_PALETTE) {
		245	uint32_t palette = (uint32_t ) newpic->data[1];
		246	for (i = 0; i < 256; i++) {
		247	palette[i] = 0xFFU << 24 \| bytestream2_get_be24(&gb);
		248	}
		249	newpic->palette_has_changed = 1;
		250	} else {
		251	if (oldpic->data[1])
		252	memcpy(newpic->data[1], oldpic->data[1], 256 * 4);
		253	}
		254
		255	if ((ret = av_frame_ref(data, newpic)) < 0)
		256	return ret;
		257	*got_frame = 1;
		258
		259	return buf_size;
		260	}
		261
		262	AVCodec ff_c93_decoder = {
		263	.name = "c93",
		264	.long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
		265	.type = AVMEDIA_TYPE_VIDEO,
		266	.id = AV_CODEC_ID_C93,
		267	.priv_data_size = sizeof(C93DecoderContext),
		268	.init = decode_init,
		269	.close = decode_end,
		270	.decode = decode_frame,
		271	.capabilities = AV_CODEC_CAP_DR1,
		272	};

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(root)/contrib/sdk/sources/ffmpeg/ffmpeg-2.8/libavcodec/c93.c – Rev 6147