8bps.c
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1 /*
2  * Quicktime Planar RGB (8BPS) Video Decoder
3  * Copyright (C) 2003 Roberto Togni
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
34 #include <stdio.h>
35 #include <stdlib.h>
36 
37 #include "libavutil/intreadwrite.h"
38 #include "avcodec.h"
39 
40 
42 
43 /*
44  * Decoder context
45  */
46 typedef struct EightBpsContext {
47 
50 
51  unsigned char planes;
52  unsigned char planemap[4];
53 
54  uint32_t pal[256];
56 
57 
58 /*
59  *
60  * Decode a frame
61  *
62  */
63 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
64 {
65  const uint8_t *buf = avpkt->data;
66  int buf_size = avpkt->size;
67  EightBpsContext * const c = avctx->priv_data;
68  const unsigned char *encoded = buf;
69  unsigned char *pixptr, *pixptr_end;
70  unsigned int height = avctx->height; // Real image height
71  unsigned int dlen, p, row;
72  const unsigned char *lp, *dp;
73  unsigned char count;
74  unsigned int px_inc;
75  unsigned int planes = c->planes;
76  unsigned char *planemap = c->planemap;
77 
78  if(c->pic.data[0])
79  avctx->release_buffer(avctx, &c->pic);
80 
81  c->pic.reference = 0;
83  if(avctx->get_buffer(avctx, &c->pic) < 0){
84  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
85  return -1;
86  }
87 
88  /* Set data pointer after line lengths */
89  dp = encoded + planes * (height << 1);
90 
91  /* Ignore alpha plane, don't know what to do with it */
92  if (planes == 4)
93  planes--;
94 
95  px_inc = planes + (avctx->pix_fmt == PIX_FMT_RGB32);
96 
97  for (p = 0; p < planes; p++) {
98  /* Lines length pointer for this plane */
99  lp = encoded + p * (height << 1);
100 
101  /* Decode a plane */
102  for(row = 0; row < height; row++) {
103  pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
104  pixptr_end = pixptr + c->pic.linesize[0];
105  dlen = av_be2ne16(*(const unsigned short *)(lp+row*2));
106  /* Decode a row of this plane */
107  while(dlen > 0) {
108  if(dp + 1 >= buf+buf_size) return -1;
109  if ((count = *dp++) <= 127) {
110  count++;
111  dlen -= count + 1;
112  if (pixptr + count * px_inc > pixptr_end)
113  break;
114  if(dp + count > buf+buf_size) return -1;
115  while(count--) {
116  *pixptr = *dp++;
117  pixptr += px_inc;
118  }
119  } else {
120  count = 257 - count;
121  if (pixptr + count * px_inc > pixptr_end)
122  break;
123  while(count--) {
124  *pixptr = *dp;
125  pixptr += px_inc;
126  }
127  dp++;
128  dlen -= 2;
129  }
130  }
131  }
132  }
133 
134  if (avctx->bits_per_coded_sample <= 8) {
135  const uint8_t *pal = av_packet_get_side_data(avpkt,
137  NULL);
138  if (pal) {
139  c->pic.palette_has_changed = 1;
140  memcpy(c->pal, pal, AVPALETTE_SIZE);
141  }
142 
143  memcpy (c->pic.data[1], c->pal, AVPALETTE_SIZE);
144  }
145 
146  *data_size = sizeof(AVFrame);
147  *(AVFrame*)data = c->pic;
148 
149  /* always report that the buffer was completely consumed */
150  return buf_size;
151 }
152 
153 
154 /*
155  *
156  * Init 8BPS decoder
157  *
158  */
160 {
161  EightBpsContext * const c = avctx->priv_data;
162 
163  c->avctx = avctx;
164 
165  c->pic.data[0] = NULL;
166 
167  switch (avctx->bits_per_coded_sample) {
168  case 8:
169  avctx->pix_fmt = PIX_FMT_PAL8;
170  c->planes = 1;
171  c->planemap[0] = 0; // 1st plane is palette indexes
172  break;
173  case 24:
174  avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
175  c->planes = 3;
176  c->planemap[0] = 2; // 1st plane is red
177  c->planemap[1] = 1; // 2nd plane is green
178  c->planemap[2] = 0; // 3rd plane is blue
179  break;
180  case 32:
181  avctx->pix_fmt = PIX_FMT_RGB32;
182  c->planes = 4;
183 #if HAVE_BIGENDIAN
184  c->planemap[0] = 1; // 1st plane is red
185  c->planemap[1] = 2; // 2nd plane is green
186  c->planemap[2] = 3; // 3rd plane is blue
187  c->planemap[3] = 0; // 4th plane is alpha???
188 #else
189  c->planemap[0] = 2; // 1st plane is red
190  c->planemap[1] = 1; // 2nd plane is green
191  c->planemap[2] = 0; // 3rd plane is blue
192  c->planemap[3] = 3; // 4th plane is alpha???
193 #endif
194  break;
195  default:
196  av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_coded_sample);
197  return -1;
198  }
199 
200  return 0;
201 }
202 
203 
204 
205 
206 /*
207  *
208  * Uninit 8BPS decoder
209  *
210  */
212 {
213  EightBpsContext * const c = avctx->priv_data;
214 
215  if (c->pic.data[0])
216  avctx->release_buffer(avctx, &c->pic);
217 
218  return 0;
219 }
220 
221 
222 
224  .name = "8bps",
225  .type = AVMEDIA_TYPE_VIDEO,
226  .id = CODEC_ID_8BPS,
227  .priv_data_size = sizeof(EightBpsContext),
228  .init = decode_init,
229  .close = decode_end,
230  .decode = decode_frame,
231  .capabilities = CODEC_CAP_DR1,
232  .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
233 };