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rpza.c
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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 
47 typedef struct RpzaContext {
48 
51 
53 } RpzaContext;
54 
55 #define ADVANCE_BLOCK() \
56 { \
57  pixel_ptr += 4; \
58  if (pixel_ptr >= width) \
59  { \
60  pixel_ptr = 0; \
61  row_ptr += stride * 4; \
62  } \
63  total_blocks--; \
64  if (total_blocks < 0) \
65  { \
66  av_log(s->avctx, AV_LOG_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
67  return; \
68  } \
69 }
70 
72 {
73  int width = s->avctx->width;
74  int stride = s->frame->linesize[0] / 2;
75  int row_inc = stride - 4;
76  int chunk_size;
77  uint16_t colorA = 0, colorB;
78  uint16_t color4[4];
79  uint16_t ta, tb;
80  uint16_t *pixels = (uint16_t *)s->frame->data[0];
81 
82  int row_ptr = 0;
83  int pixel_ptr = -4;
84  int block_ptr;
85  int pixel_x, pixel_y;
86  int total_blocks;
87 
88  /* First byte is always 0xe1. Warn if it's different */
89  if (bytestream2_peek_byte(&s->gb) != 0xe1)
90  av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
91  bytestream2_peek_byte(&s->gb));
92 
93  /* Get chunk size, ingnoring first byte */
94  chunk_size = bytestream2_get_be32(&s->gb) & 0x00FFFFFF;
95 
96  /* If length mismatch use size from MOV file and try to decode anyway */
97  if (chunk_size != bytestream2_get_bytes_left(&s->gb) + 4)
99  "MOV chunk size %d != encoded chunk size %d\n",
100  chunk_size,
102  );
103 
104  /* Number of 4x4 blocks in frame. */
105  total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
106 
107  /* Process chunk data */
108  while (bytestream2_get_bytes_left(&s->gb)) {
109  uint8_t opcode = bytestream2_get_byte(&s->gb); /* Get opcode */
110 
111  int n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
112 
113  /* If opcode MSbit is 0, we need more data to decide what to do */
114  if ((opcode & 0x80) == 0) {
115  colorA = (opcode << 8) | bytestream2_get_byte(&s->gb);
116  opcode = 0;
117  if ((bytestream2_peek_byte(&s->gb) & 0x80) != 0) {
118  /* Must behave as opcode 110xxxxx, using colorA computed
119  * above. Use fake opcode 0x20 to enter switch block at
120  * the right place */
121  opcode = 0x20;
122  n_blocks = 1;
123  }
124  }
125 
126  n_blocks = FFMIN(n_blocks, total_blocks);
127 
128  switch (opcode & 0xe0) {
129 
130  /* Skip blocks */
131  case 0x80:
132  while (n_blocks--) {
133  ADVANCE_BLOCK();
134  }
135  break;
136 
137  /* Fill blocks with one color */
138  case 0xa0:
139  colorA = bytestream2_get_be16(&s->gb);
140  while (n_blocks--) {
141  ADVANCE_BLOCK()
142  block_ptr = row_ptr + pixel_ptr;
143  for (pixel_y = 0; pixel_y < 4; pixel_y++) {
144  for (pixel_x = 0; pixel_x < 4; pixel_x++){
145  pixels[block_ptr] = colorA;
146  block_ptr++;
147  }
148  block_ptr += row_inc;
149  }
150  }
151  break;
152 
153  /* Fill blocks with 4 colors */
154  case 0xc0:
155  colorA = bytestream2_get_be16(&s->gb);
156  case 0x20:
157  colorB = bytestream2_get_be16(&s->gb);
158 
159  /* sort out the colors */
160  color4[0] = colorB;
161  color4[1] = 0;
162  color4[2] = 0;
163  color4[3] = colorA;
164 
165  /* red components */
166  ta = (colorA >> 10) & 0x1F;
167  tb = (colorB >> 10) & 0x1F;
168  color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
169  color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
170 
171  /* green components */
172  ta = (colorA >> 5) & 0x1F;
173  tb = (colorB >> 5) & 0x1F;
174  color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
175  color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
176 
177  /* blue components */
178  ta = colorA & 0x1F;
179  tb = colorB & 0x1F;
180  color4[1] |= ((11 * ta + 21 * tb) >> 5);
181  color4[2] |= ((21 * ta + 11 * tb) >> 5);
182 
183  if (bytestream2_get_bytes_left(&s->gb) < n_blocks * 4)
184  return;
185  while (n_blocks--) {
186  ADVANCE_BLOCK();
187  block_ptr = row_ptr + pixel_ptr;
188  for (pixel_y = 0; pixel_y < 4; pixel_y++) {
189  uint8_t index = bytestream2_get_byteu(&s->gb);
190  for (pixel_x = 0; pixel_x < 4; pixel_x++){
191  uint8_t idx = (index >> (2 * (3 - pixel_x))) & 0x03;
192  pixels[block_ptr] = color4[idx];
193  block_ptr++;
194  }
195  block_ptr += row_inc;
196  }
197  }
198  break;
199 
200  /* Fill block with 16 colors */
201  case 0x00:
202  if (bytestream2_get_bytes_left(&s->gb) < 30)
203  return;
204  ADVANCE_BLOCK();
205  block_ptr = row_ptr + pixel_ptr;
206  for (pixel_y = 0; pixel_y < 4; pixel_y++) {
207  for (pixel_x = 0; pixel_x < 4; pixel_x++){
208  /* We already have color of upper left pixel */
209  if ((pixel_y != 0) || (pixel_x != 0))
210  colorA = bytestream2_get_be16u(&s->gb);
211  pixels[block_ptr] = colorA;
212  block_ptr++;
213  }
214  block_ptr += row_inc;
215  }
216  break;
217 
218  /* Unknown opcode */
219  default:
220  av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
221  " Skip remaining %d bytes of chunk data.\n", opcode,
223  return;
224  } /* Opcode switch */
225  }
226 }
227 
229 {
230  RpzaContext *s = avctx->priv_data;
231 
232  s->avctx = avctx;
233  avctx->pix_fmt = AV_PIX_FMT_RGB555;
234 
235  s->frame = av_frame_alloc();
236  if (!s->frame)
237  return AVERROR(ENOMEM);
238 
239  return 0;
240 }
241 
243  void *data, int *got_frame,
244  AVPacket *avpkt)
245 {
246  RpzaContext *s = avctx->priv_data;
247  int ret;
248 
249  bytestream2_init(&s->gb, avpkt->data, avpkt->size);
250 
251  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
252  return ret;
253 
255 
256  if ((ret = av_frame_ref(data, s->frame)) < 0)
257  return ret;
258 
259  *got_frame = 1;
260 
261  /* always report that the buffer was completely consumed */
262  return avpkt->size;
263 }
264 
266 {
267  RpzaContext *s = avctx->priv_data;
268 
269  av_frame_free(&s->frame);
270 
271  return 0;
272 }
273 
275  .name = "rpza",
276  .long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
277  .type = AVMEDIA_TYPE_VIDEO,
278  .id = AV_CODEC_ID_RPZA,
279  .priv_data_size = sizeof(RpzaContext),
281  .close = rpza_decode_end,
283  .capabilities = CODEC_CAP_DR1,
284 };