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path: root/libavcodec/rpza.c (plain)
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1/*
2 * Quicktime Video (RPZA) Video Decoder
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 * QT RPZA Video Decoder by Roberto Togni
25 * For more information about the RPZA format, visit:
26 * http://www.pcisys.net/~melanson/codecs/
27 *
28 * The RPZA decoder outputs RGB555 colorspace data.
29 *
30 * Note that this decoder reads big endian RGB555 pixel values from the
31 * bytestream, arranges them in the host's endian order, and outputs
32 * them to the final rendered map in the same host endian order. This is
33 * intended behavior as the libavcodec documentation states that RGB555
34 * pixels shall be stored in native CPU endianness.
35 */
36
37#include <stdint.h>
38#include <stdio.h>
39#include <stdlib.h>
40#include <string.h>
41
42#include "libavutil/internal.h"
43#include "avcodec.h"
44#include "bytestream.h"
45#include "internal.h"
46
47typedef struct RpzaContext {
48
49 AVCodecContext *avctx;
50 AVFrame *frame;
51
52 GetByteContext gb;
53} RpzaContext;
54
55#define CHECK_BLOCK() \
56 if (total_blocks < 1) { \
57 av_log(s->avctx, AV_LOG_ERROR, \
58 "Block counter just went negative (this should not happen)\n"); \
59 return AVERROR_INVALIDDATA; \
60 } \
61
62#define ADVANCE_BLOCK() \
63 { \
64 pixel_ptr += 4; \
65 if (pixel_ptr >= width) \
66 { \
67 pixel_ptr = 0; \
68 row_ptr += stride * 4; \
69 } \
70 total_blocks--; \
71 }
72
73static int rpza_decode_stream(RpzaContext *s)
74{
75 int width = s->avctx->width;
76 int stride = s->frame->linesize[0] / 2;
77 int row_inc = stride - 4;
78 int chunk_size;
79 uint16_t colorA = 0, colorB;
80 uint16_t color4[4];
81 uint16_t ta, tb;
82 uint16_t *pixels = (uint16_t *)s->frame->data[0];
83
84 int row_ptr = 0;
85 int pixel_ptr = 0;
86 int block_ptr;
87 int pixel_x, pixel_y;
88 int total_blocks;
89
90 /* First byte is always 0xe1. Warn if it's different */
91 if (bytestream2_peek_byte(&s->gb) != 0xe1)
92 av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
93 bytestream2_peek_byte(&s->gb));
94
95 /* Get chunk size, ignoring first byte */
96 chunk_size = bytestream2_get_be32(&s->gb) & 0x00FFFFFF;
97
98 /* If length mismatch use size from MOV file and try to decode anyway */
99 if (chunk_size != bytestream2_get_bytes_left(&s->gb) + 4)
100 av_log(s->avctx, AV_LOG_WARNING,
101 "MOV chunk size %d != encoded chunk size %d\n",
102 chunk_size,
103 bytestream2_get_bytes_left(&s->gb) + 4
104 );
105
106 /* Number of 4x4 blocks in frame. */
107 total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
108
109 /* Process chunk data */
110 while (bytestream2_get_bytes_left(&s->gb)) {
111 uint8_t opcode = bytestream2_get_byte(&s->gb); /* Get opcode */
112
113 int n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
114
115 /* If opcode MSbit is 0, we need more data to decide what to do */
116 if ((opcode & 0x80) == 0) {
117 colorA = (opcode << 8) | bytestream2_get_byte(&s->gb);
118 opcode = 0;
119 if ((bytestream2_peek_byte(&s->gb) & 0x80) != 0) {
120 /* Must behave as opcode 110xxxxx, using colorA computed
121 * above. Use fake opcode 0x20 to enter switch block at
122 * the right place */
123 opcode = 0x20;
124 n_blocks = 1;
125 }
126 }
127
128 n_blocks = FFMIN(n_blocks, total_blocks);
129
130 switch (opcode & 0xe0) {
131
132 /* Skip blocks */
133 case 0x80:
134 while (n_blocks--) {
135 CHECK_BLOCK();
136 ADVANCE_BLOCK();
137 }
138 break;
139
140 /* Fill blocks with one color */
141 case 0xa0:
142 colorA = bytestream2_get_be16(&s->gb);
143 while (n_blocks--) {
144 CHECK_BLOCK();
145 block_ptr = row_ptr + pixel_ptr;
146 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
147 for (pixel_x = 0; pixel_x < 4; pixel_x++){
148 pixels[block_ptr] = colorA;
149 block_ptr++;
150 }
151 block_ptr += row_inc;
152 }
153 ADVANCE_BLOCK();
154 }
155 break;
156
157 /* Fill blocks with 4 colors */
158 case 0xc0:
159 colorA = bytestream2_get_be16(&s->gb);
160 case 0x20:
161 colorB = bytestream2_get_be16(&s->gb);
162
163 /* sort out the colors */
164 color4[0] = colorB;
165 color4[1] = 0;
166 color4[2] = 0;
167 color4[3] = colorA;
168
169 /* red components */
170 ta = (colorA >> 10) & 0x1F;
171 tb = (colorB >> 10) & 0x1F;
172 color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
173 color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
174
175 /* green components */
176 ta = (colorA >> 5) & 0x1F;
177 tb = (colorB >> 5) & 0x1F;
178 color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
179 color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
180
181 /* blue components */
182 ta = colorA & 0x1F;
183 tb = colorB & 0x1F;
184 color4[1] |= ((11 * ta + 21 * tb) >> 5);
185 color4[2] |= ((21 * ta + 11 * tb) >> 5);
186
187 if (bytestream2_get_bytes_left(&s->gb) < n_blocks * 4)
188 return AVERROR_INVALIDDATA;
189 while (n_blocks--) {
190 CHECK_BLOCK();
191 block_ptr = row_ptr + pixel_ptr;
192 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
193 uint8_t index = bytestream2_get_byteu(&s->gb);
194 for (pixel_x = 0; pixel_x < 4; pixel_x++){
195 uint8_t idx = (index >> (2 * (3 - pixel_x))) & 0x03;
196 pixels[block_ptr] = color4[idx];
197 block_ptr++;
198 }
199 block_ptr += row_inc;
200 }
201 ADVANCE_BLOCK();
202 }
203 break;
204
205 /* Fill block with 16 colors */
206 case 0x00:
207 if (bytestream2_get_bytes_left(&s->gb) < 30)
208 return AVERROR_INVALIDDATA;
209 CHECK_BLOCK();
210 block_ptr = row_ptr + pixel_ptr;
211 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
212 for (pixel_x = 0; pixel_x < 4; pixel_x++){
213 /* We already have color of upper left pixel */
214 if ((pixel_y != 0) || (pixel_x != 0))
215 colorA = bytestream2_get_be16u(&s->gb);
216 pixels[block_ptr] = colorA;
217 block_ptr++;
218 }
219 block_ptr += row_inc;
220 }
221 ADVANCE_BLOCK();
222 break;
223
224 /* Unknown opcode */
225 default:
226 av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
227 " Skip remaining %d bytes of chunk data.\n", opcode,
228 bytestream2_get_bytes_left(&s->gb));
229 return AVERROR_INVALIDDATA;
230 } /* Opcode switch */
231 }
232
233 return 0;
234}
235
236static av_cold int rpza_decode_init(AVCodecContext *avctx)
237{
238 RpzaContext *s = avctx->priv_data;
239
240 s->avctx = avctx;
241 avctx->pix_fmt = AV_PIX_FMT_RGB555;
242
243 s->frame = av_frame_alloc();
244 if (!s->frame)
245 return AVERROR(ENOMEM);
246
247 return 0;
248}
249
250static int rpza_decode_frame(AVCodecContext *avctx,
251 void *data, int *got_frame,
252 AVPacket *avpkt)
253{
254 RpzaContext *s = avctx->priv_data;
255 int ret;
256
257 bytestream2_init(&s->gb, avpkt->data, avpkt->size);
258
259 if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
260 return ret;
261
262 ret = rpza_decode_stream(s);
263 if (ret < 0)
264 return ret;
265
266 if ((ret = av_frame_ref(data, s->frame)) < 0)
267 return ret;
268
269 *got_frame = 1;
270
271 /* always report that the buffer was completely consumed */
272 return avpkt->size;
273}
274
275static av_cold int rpza_decode_end(AVCodecContext *avctx)
276{
277 RpzaContext *s = avctx->priv_data;
278
279 av_frame_free(&s->frame);
280
281 return 0;
282}
283
284AVCodec ff_rpza_decoder = {
285 .name = "rpza",
286 .long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
287 .type = AVMEDIA_TYPE_VIDEO,
288 .id = AV_CODEC_ID_RPZA,
289 .priv_data_size = sizeof(RpzaContext),
290 .init = rpza_decode_init,
291 .close = rpza_decode_end,
292 .decode = rpza_decode_frame,
293 .capabilities = AV_CODEC_CAP_DR1,
294};
295
generated by cgit at 2024-05-17 08:36:03 (GMT)