FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
8bps.c
Go to the documentation of this file.
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 {
50 
51  unsigned char planes;
52  unsigned char planemap[4];
53 
54  uint32_t pal[256];
56 
57 static int decode_frame(AVCodecContext *avctx, void *data,
58  int *got_frame, AVPacket *avpkt)
59 {
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 (c->pic.data[0])
74  avctx->release_buffer(avctx, &c->pic);
75 
76  c->pic.reference = 0;
78  if ((ret = ff_get_buffer(avctx, &c->pic)) < 0) {
79  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
80  return ret;
81  }
82 
83  /* Set data pointer after line lengths */
84  dp = encoded + planes * (height << 1);
85 
86  for (p = 0; p < planes; p++) {
87  /* Lines length pointer for this plane */
88  lp = encoded + p * (height << 1);
89 
90  /* Decode a plane */
91  for (row = 0; row < height; row++) {
92  pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
93  pixptr_end = pixptr + c->pic.linesize[0];
94  if(lp - encoded + row*2 + 1 >= buf_size)
95  return -1;
96  dlen = av_be2ne16(*(const unsigned short *)(lp + row * 2));
97  /* Decode a row of this plane */
98  while (dlen > 0) {
99  if (dp + 1 >= buf + buf_size)
100  return AVERROR_INVALIDDATA;
101  if ((count = *dp++) <= 127) {
102  count++;
103  dlen -= count + 1;
104  if (pixptr + count * planes > pixptr_end)
105  break;
106  if (dp + count > buf + buf_size)
107  return AVERROR_INVALIDDATA;
108  while (count--) {
109  *pixptr = *dp++;
110  pixptr += planes;
111  }
112  } else {
113  count = 257 - count;
114  if (pixptr + count * planes > pixptr_end)
115  break;
116  while (count--) {
117  *pixptr = *dp;
118  pixptr += planes;
119  }
120  dp++;
121  dlen -= 2;
122  }
123  }
124  }
125  }
126 
127  if (avctx->bits_per_coded_sample <= 8) {
128  const uint8_t *pal = av_packet_get_side_data(avpkt,
130  NULL);
131  if (pal) {
132  c->pic.palette_has_changed = 1;
133  memcpy(c->pal, pal, AVPALETTE_SIZE);
134  }
135 
136  memcpy (c->pic.data[1], c->pal, AVPALETTE_SIZE);
137  }
138 
139  *got_frame = 1;
140  *(AVFrame*)data = c->pic;
141 
142  /* always report that the buffer was completely consumed */
143  return buf_size;
144 }
145 
147 {
148  EightBpsContext * const c = avctx->priv_data;
149 
150  c->avctx = avctx;
151  c->pic.data[0] = NULL;
152 
154  switch (avctx->bits_per_coded_sample) {
155  case 8:
156  avctx->pix_fmt = AV_PIX_FMT_PAL8;
157  c->planes = 1;
158  c->planemap[0] = 0; // 1st plane is palette indexes
159  break;
160  case 24:
161  avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
162  c->planes = 3;
163  c->planemap[0] = 2; // 1st plane is red
164  c->planemap[1] = 1; // 2nd plane is green
165  c->planemap[2] = 0; // 3rd plane is blue
166  break;
167  case 32:
168  avctx->pix_fmt = AV_PIX_FMT_RGB32;
169  c->planes = 4;
170 #if HAVE_BIGENDIAN
171  c->planemap[0] = 1; // 1st plane is red
172  c->planemap[1] = 2; // 2nd plane is green
173  c->planemap[2] = 3; // 3rd plane is blue
174  c->planemap[3] = 0; // 4th plane is alpha
175 #else
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  c->planemap[3] = 3; // 4th plane is alpha
180 #endif
181  break;
182  default:
183  av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",
184  avctx->bits_per_coded_sample);
185  return AVERROR_INVALIDDATA;
186  }
187 
188  return 0;
189 }
190 
192 {
193  EightBpsContext * const c = avctx->priv_data;
194 
195  if (c->pic.data[0])
196  avctx->release_buffer(avctx, &c->pic);
197 
198  return 0;
199 }
200 
202  .name = "8bps",
203  .type = AVMEDIA_TYPE_VIDEO,
204  .id = AV_CODEC_ID_8BPS,
205  .priv_data_size = sizeof(EightBpsContext),
206  .init = decode_init,
207  .close = decode_end,
208  .decode = decode_frame,
209  .capabilities = CODEC_CAP_DR1,
210  .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
211 };