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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 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 8BPS Video Decoder by Roberto Togni
25  * For more information about the 8BPS format, visit:
26  * http://www.pcisys.net/~melanson/codecs/
27  *
28  * Supports: PAL8 (RGB 8bpp, paletted)
29  * : BGR24 (RGB 24bpp) (can also output it as RGB32)
30  * : RGB32 (RGB 32bpp, 4th plane is alpha)
31  *
32  */
33 
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;
68  unsigned char count;
69  unsigned int planes = c->planes;
70  unsigned char *planemap = c->planemap;
71  int ret;
72 
73  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
74  return ret;
75 
76  /* Set data pointer after line lengths */
77  dp = encoded + planes * (height << 1);
78 
79  for (p = 0; p < planes; p++) {
80  /* Lines length pointer for this plane */
81  lp = encoded + p * (height << 1);
82 
83  /* Decode a plane */
84  for (row = 0; row < height; row++) {
85  pixptr = frame->data[0] + row * frame->linesize[0] + planemap[p];
86  pixptr_end = pixptr + frame->linesize[0];
87  if(lp - encoded + row*2 + 1 >= buf_size)
88  return -1;
89  dlen = av_be2ne16(*(const unsigned short *)(lp + row * 2));
90  /* Decode a row of this plane */
91  while (dlen > 0) {
92  if (dp + 1 >= buf + buf_size)
93  return AVERROR_INVALIDDATA;
94  if ((count = *dp++) <= 127) {
95  count++;
96  dlen -= count + 1;
97  if (pixptr + count * planes > pixptr_end)
98  break;
99  if (dp + count > buf + buf_size)
100  return AVERROR_INVALIDDATA;
101  while (count--) {
102  *pixptr = *dp++;
103  pixptr += planes;
104  }
105  } else {
106  count = 257 - count;
107  if (pixptr + count * planes > pixptr_end)
108  break;
109  while (count--) {
110  *pixptr = *dp;
111  pixptr += planes;
112  }
113  dp++;
114  dlen -= 2;
115  }
116  }
117  }
118  }
119 
120  if (avctx->bits_per_coded_sample <= 8) {
121  const uint8_t *pal = av_packet_get_side_data(avpkt,
123  NULL);
124  if (pal) {
125  frame->palette_has_changed = 1;
126  memcpy(c->pal, pal, AVPALETTE_SIZE);
127  }
128 
129  memcpy (frame->data[1], c->pal, AVPALETTE_SIZE);
130  }
131 
132  *got_frame = 1;
133 
134  /* always report that the buffer was completely consumed */
135  return buf_size;
136 }
137 
139 {
140  EightBpsContext * const c = avctx->priv_data;
141 
142  c->avctx = avctx;
143 
144  switch (avctx->bits_per_coded_sample) {
145  case 8:
146  avctx->pix_fmt = AV_PIX_FMT_PAL8;
147  c->planes = 1;
148  c->planemap[0] = 0; // 1st plane is palette indexes
149  break;
150  case 24:
151  avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
152  c->planes = 3;
153  c->planemap[0] = 2; // 1st plane is red
154  c->planemap[1] = 1; // 2nd plane is green
155  c->planemap[2] = 0; // 3rd plane is blue
156  break;
157  case 32:
158  avctx->pix_fmt = AV_PIX_FMT_RGB32;
159  c->planes = 4;
160 #if HAVE_BIGENDIAN
161  c->planemap[0] = 1; // 1st plane is red
162  c->planemap[1] = 2; // 2nd plane is green
163  c->planemap[2] = 3; // 3rd plane is blue
164  c->planemap[3] = 0; // 4th plane is alpha
165 #else
166  c->planemap[0] = 2; // 1st plane is red
167  c->planemap[1] = 1; // 2nd plane is green
168  c->planemap[2] = 0; // 3rd plane is blue
169  c->planemap[3] = 3; // 4th plane is alpha
170 #endif
171  break;
172  default:
173  av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",
174  avctx->bits_per_coded_sample);
175  return AVERROR_INVALIDDATA;
176  }
177 
178  return 0;
179 }
180 
182  .name = "8bps",
183  .type = AVMEDIA_TYPE_VIDEO,
184  .id = AV_CODEC_ID_8BPS,
185  .priv_data_size = sizeof(EightBpsContext),
186  .init = decode_init,
187  .decode = decode_frame,
188  .capabilities = CODEC_CAP_DR1,
189  .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
190 };