Libav
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 #include <string.h>
37 
38 #include "libavutil/internal.h"
39 #include "libavutil/intreadwrite.h"
40 #include "avcodec.h"
41 #include "internal.h"
42 
43 
44 static const enum AVPixelFormat pixfmt_rgb24[] = {
46 
47 typedef struct EightBpsContext {
49 
50  unsigned char planes;
51  unsigned char planemap[4];
52 
53  uint32_t pal[256];
55 
56 static int decode_frame(AVCodecContext *avctx, void *data,
57  int *got_frame, AVPacket *avpkt)
58 {
59  AVFrame *frame = data;
60  const uint8_t *buf = avpkt->data;
61  int buf_size = avpkt->size;
62  EightBpsContext * const c = avctx->priv_data;
63  const unsigned char *encoded = buf;
64  unsigned char *pixptr, *pixptr_end;
65  unsigned int height = avctx->height; // Real image height
66  unsigned int dlen, p, row;
67  const unsigned char *lp, *dp, *ep;
68  unsigned char count;
69  unsigned int px_inc;
70  unsigned int planes = c->planes;
71  unsigned char *planemap = c->planemap;
72  int ret;
73 
74  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
75  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
76  return ret;
77  }
78 
79  ep = encoded + buf_size;
80 
81  /* Set data pointer after line lengths */
82  dp = encoded + planes * (height << 1);
83 
84  /* Ignore alpha plane, don't know what to do with it */
85  if (planes == 4)
86  planes--;
87 
88  px_inc = planes + (avctx->pix_fmt == AV_PIX_FMT_RGB32);
89 
90  for (p = 0; p < planes; p++) {
91  /* Lines length pointer for this plane */
92  lp = encoded + p * (height << 1);
93 
94  /* Decode a plane */
95  for (row = 0; row < height; row++) {
96  pixptr = frame->data[0] + row * frame->linesize[0] + planemap[p];
97  pixptr_end = pixptr + frame->linesize[0];
98  if (ep - lp < row * 2 + 2)
99  return AVERROR_INVALIDDATA;
100  dlen = av_be2ne16(*(const unsigned short *)(lp + row * 2));
101  /* Decode a row of this plane */
102  while (dlen > 0) {
103  if (ep - dp <= 1)
104  return AVERROR_INVALIDDATA;
105  if ((count = *dp++) <= 127) {
106  count++;
107  dlen -= count + 1;
108  if (pixptr_end - pixptr < count * px_inc)
109  break;
110  if (ep - dp < count)
111  return AVERROR_INVALIDDATA;
112  while (count--) {
113  *pixptr = *dp++;
114  pixptr += px_inc;
115  }
116  } else {
117  count = 257 - count;
118  if (pixptr_end - pixptr < count * px_inc)
119  break;
120  while (count--) {
121  *pixptr = *dp;
122  pixptr += px_inc;
123  }
124  dp++;
125  dlen -= 2;
126  }
127  }
128  }
129  }
130 
131  if (avctx->bits_per_coded_sample <= 8) {
132  const uint8_t *pal = av_packet_get_side_data(avpkt,
134  NULL);
135  if (pal) {
136  frame->palette_has_changed = 1;
137  memcpy(c->pal, pal, AVPALETTE_SIZE);
138  }
139 
140  memcpy (frame->data[1], c->pal, AVPALETTE_SIZE);
141  }
142 
143  *got_frame = 1;
144 
145  /* always report that the buffer was completely consumed */
146  return buf_size;
147 }
148 
150 {
151  EightBpsContext * const c = avctx->priv_data;
152 
153  c->avctx = avctx;
154 
155  switch (avctx->bits_per_coded_sample) {
156  case 8:
157  avctx->pix_fmt = AV_PIX_FMT_PAL8;
158  c->planes = 1;
159  c->planemap[0] = 0; // 1st plane is palette indexes
160  break;
161  case 24:
162  avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
163  c->planes = 3;
164  c->planemap[0] = 2; // 1st plane is red
165  c->planemap[1] = 1; // 2nd plane is green
166  c->planemap[2] = 0; // 3rd plane is blue
167  break;
168  case 32:
169  avctx->pix_fmt = AV_PIX_FMT_RGB32;
170  c->planes = 4;
171  /* handle planemap setup later for decoding rgb24 data as rbg32 */
172  break;
173  default:
174  av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",
175  avctx->bits_per_coded_sample);
176  return AVERROR_INVALIDDATA;
177  }
178 
179  if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
180  c->planemap[0] = HAVE_BIGENDIAN ? 1 : 2; // 1st plane is red
181  c->planemap[1] = HAVE_BIGENDIAN ? 2 : 1; // 2nd plane is green
182  c->planemap[2] = HAVE_BIGENDIAN ? 3 : 0; // 3rd plane is blue
183  c->planemap[3] = HAVE_BIGENDIAN ? 0 : 3; // 4th plane is alpha???
184  }
185  return 0;
186 }
187 
189  .name = "8bps",
190  .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
191  .type = AVMEDIA_TYPE_VIDEO,
192  .id = AV_CODEC_ID_8BPS,
193  .priv_data_size = sizeof(EightBpsContext),
194  .init = decode_init,
195  .decode = decode_frame,
196  .capabilities = CODEC_CAP_DR1,
197 };