9509f42ad572629a387d507f1f7225088e79f630
[libav.git] / libavcodec / 8bps.c
1 /*
2 * Quicktime Planar RGB (8BPS) Video Decoder
3 * Copyright (C) 2003 Roberto Togni
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 */
20
21 /**
22 * @file 8bps.c
23 * QT 8BPS Video Decoder by Roberto Togni <rtogni at bresciaonline dot it>
24 * For more information about the 8BPS format, visit:
25 * http://www.pcisys.net/~melanson/codecs/
26 *
27 * Supports: PAL8 (RGB 8bpp, paletted)
28 * : BGR24 (RGB 24bpp) (can also output it as RGBA32)
29 * : RGBA32 (RGB 32bpp, 4th plane is probably alpha and it's ignored)
30 *
31 */
32
33 #include <stdio.h>
34 #include <stdlib.h>
35
36 #include "common.h"
37 #include "avcodec.h"
38
39
40 const enum PixelFormat pixfmt_rgb24[] = {PIX_FMT_BGR24, PIX_FMT_RGBA32, -1};
41
42 /*
43 * Decoder context
44 */
45 typedef struct EightBpsContext {
46
47 AVCodecContext *avctx;
48 AVFrame pic;
49
50 unsigned char planes;
51 unsigned char planemap[4];
52 } EightBpsContext;
53
54
55 /*
56 *
57 * Decode a frame
58 *
59 */
60 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
61 {
62 EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;
63 unsigned char *encoded = (unsigned char *)buf;
64 unsigned char *pixptr;
65 unsigned int height = avctx->height; // Real image height
66 unsigned int dlen, p, row;
67 unsigned char *lp, *dp;
68 unsigned char count;
69 unsigned int px_inc;
70 unsigned int planes = c->planes;
71 unsigned char *planemap = c->planemap;
72
73
74 /* no supplementary picture */
75 if (buf_size == 0)
76 return 0;
77
78 if(c->pic.data[0])
79 avctx->release_buffer(avctx, &c->pic);
80
81 c->pic.reference = 0;
82 c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
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_RGBA32);
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 dlen = be2me_16(*(unsigned short *)(lp+row*2));
105 /* Decode a row of this plane */
106 while(dlen > 0) {
107 if ((count = *dp++) <= 127) {
108 count++;
109 dlen -= count + 1;
110 while(count--) {
111 *pixptr = *dp++;
112 pixptr += px_inc;
113 }
114 } else {
115 count = 257 - count;
116 while(count--) {
117 *pixptr = *dp;
118 pixptr += px_inc;
119 }
120 dp++;
121 dlen -= 2;
122 }
123 }
124 }
125 }
126
127 if (avctx->palctrl) {
128 memcpy (c->pic.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
129 if (avctx->palctrl->palette_changed) {
130 c->pic.palette_has_changed = 1;
131 avctx->palctrl->palette_changed = 0;
132 } else
133 c->pic.palette_has_changed = 0;
134 }
135
136 *data_size = sizeof(AVFrame);
137 *(AVFrame*)data = c->pic;
138
139 /* always report that the buffer was completely consumed */
140 return buf_size;
141 }
142
143
144 /*
145 *
146 * Init 8BPS decoder
147 *
148 */
149 static int decode_init(AVCodecContext *avctx)
150 {
151 EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;
152
153 c->avctx = avctx;
154 avctx->has_b_frames = 0;
155
156 c->pic.data[0] = NULL;
157
158 switch (avctx->bits_per_sample) {
159 case 8:
160 avctx->pix_fmt = PIX_FMT_PAL8;
161 c->planes = 1;
162 c->planemap[0] = 0; // 1st plane is palette indexes
163 if (avctx->palctrl == NULL) {
164 av_log(avctx, AV_LOG_ERROR, "Error: PAL8 format but no palette from demuxer.\n");
165 return -1;
166 }
167 break;
168 case 24:
169 avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
170 c->planes = 3;
171 c->planemap[0] = 2; // 1st plane is red
172 c->planemap[1] = 1; // 2nd plane is green
173 c->planemap[2] = 0; // 3rd plane is blue
174 break;
175 case 32:
176 avctx->pix_fmt = PIX_FMT_RGBA32;
177 c->planes = 4;
178 #ifdef WORDS_BIGENDIAN
179 c->planemap[0] = 1; // 1st plane is red
180 c->planemap[1] = 2; // 2nd plane is green
181 c->planemap[2] = 3; // 3rd plane is blue
182 c->planemap[3] = 0; // 4th plane is alpha???
183 #else
184 c->planemap[0] = 2; // 1st plane is red
185 c->planemap[1] = 1; // 2nd plane is green
186 c->planemap[2] = 0; // 3rd plane is blue
187 c->planemap[3] = 3; // 4th plane is alpha???
188 #endif
189 break;
190 default:
191 av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_sample);
192 return -1;
193 }
194
195 return 0;
196 }
197
198
199
200
201 /*
202 *
203 * Uninit 8BPS decoder
204 *
205 */
206 static int decode_end(AVCodecContext *avctx)
207 {
208 EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;
209
210 if (c->pic.data[0])
211 avctx->release_buffer(avctx, &c->pic);
212
213 return 0;
214 }
215
216
217
218 AVCodec eightbps_decoder = {
219 "8bps",
220 CODEC_TYPE_VIDEO,
221 CODEC_ID_8BPS,
222 sizeof(EightBpsContext),
223 decode_init,
224 NULL,
225 decode_end,
226 decode_frame,
227 CODEC_CAP_DR1,
228 };