FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
indeo2.c
Go to the documentation of this file.
1 /*
2  * Intel Indeo 2 codec
3  * Copyright (c) 2005 Konstantin Shishkov
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  * Intel Indeo 2 decoder.
25  */
26 
27 #define BITSTREAM_READER_LE
28 #include "libavutil/attributes.h"
29 #include "avcodec.h"
30 #include "get_bits.h"
31 #include "indeo2data.h"
32 #include "mathops.h"
33 
34 typedef struct Ir2Context{
39 } Ir2Context;
40 
41 #define CODE_VLC_BITS 14
42 static VLC ir2_vlc;
43 
44 /* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
45 static inline int ir2_get_code(GetBitContext *gb)
46 {
47  return get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1) + 1;
48 }
49 
50 static int ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
51  const uint8_t *table)
52 {
53  int i;
54  int j;
55  int out = 0;
56  int c;
57  int t;
58 
59  if(width&1)
60  return -1;
61 
62  /* first line contain absolute values, other lines contain deltas */
63  while (out < width){
64  c = ir2_get_code(&ctx->gb);
65  if(c >= 0x80) { /* we have a run */
66  c -= 0x7F;
67  if(out + c*2 > width)
68  return -1;
69  for (i = 0; i < c * 2; i++)
70  dst[out++] = 0x80;
71  } else { /* copy two values from table */
72  dst[out++] = table[c * 2];
73  dst[out++] = table[(c * 2) + 1];
74  }
75  }
76  dst += stride;
77 
78  for (j = 1; j < height; j++){
79  out = 0;
80  while (out < width){
81  c = ir2_get_code(&ctx->gb);
82  if(c >= 0x80) { /* we have a skip */
83  c -= 0x7F;
84  if(out + c*2 > width)
85  return -1;
86  for (i = 0; i < c * 2; i++) {
87  dst[out] = dst[out - stride];
88  out++;
89  }
90  } else { /* add two deltas from table */
91  t = dst[out - stride] + (table[c * 2] - 128);
92  t= av_clip_uint8(t);
93  dst[out] = t;
94  out++;
95  t = dst[out - stride] + (table[(c * 2) + 1] - 128);
96  t= av_clip_uint8(t);
97  dst[out] = t;
98  out++;
99  }
100  }
101  dst += stride;
102  }
103  return 0;
104 }
105 
106 static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
107  const uint8_t *table)
108 {
109  int j;
110  int out = 0;
111  int c;
112  int t;
113 
114  if(width&1)
115  return -1;
116 
117  for (j = 0; j < height; j++){
118  out = 0;
119  while (out < width){
120  c = ir2_get_code(&ctx->gb);
121  if(c >= 0x80) { /* we have a skip */
122  c -= 0x7F;
123  out += c * 2;
124  } else { /* add two deltas from table */
125  t = dst[out] + (((table[c * 2] - 128)*3) >> 2);
126  t= av_clip_uint8(t);
127  dst[out] = t;
128  out++;
129  t = dst[out] + (((table[(c * 2) + 1] - 128)*3) >> 2);
130  t= av_clip_uint8(t);
131  dst[out] = t;
132  out++;
133  }
134  }
135  dst += stride;
136  }
137  return 0;
138 }
139 
141  void *data, int *got_frame,
142  AVPacket *avpkt)
143 {
144  const uint8_t *buf = avpkt->data;
145  int buf_size = avpkt->size;
146  Ir2Context * const s = avctx->priv_data;
147  AVFrame *picture = data;
148  AVFrame * const p = &s->picture;
149  int start;
150 
151  p->reference = 3;
153  if (avctx->reget_buffer(avctx, p)) {
154  av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
155  return -1;
156  }
157 
158  start = 48; /* hardcoded for now */
159 
160  if (start >= buf_size) {
161  av_log(s->avctx, AV_LOG_ERROR, "input buffer size too small (%d)\n", buf_size);
162  return AVERROR_INVALIDDATA;
163  }
164 
165  s->decode_delta = buf[18];
166 
167  /* decide whether frame uses deltas or not */
168 #ifndef BITSTREAM_READER_LE
169  for (i = 0; i < buf_size; i++)
170  buf[i] = ff_reverse[buf[i]];
171 #endif
172 
173  init_get_bits(&s->gb, buf + start, (buf_size - start) * 8);
174 
175  if (s->decode_delta) { /* intraframe */
176  ir2_decode_plane(s, avctx->width, avctx->height,
177  s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
178  /* swapped U and V */
179  ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
180  s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
181  ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
182  s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
183  } else { /* interframe */
184  ir2_decode_plane_inter(s, avctx->width, avctx->height,
185  s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
186  /* swapped U and V */
187  ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
188  s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
189  ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
190  s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
191  }
192 
193  *picture = s->picture;
194  *got_frame = 1;
195 
196  return buf_size;
197 }
198 
200  Ir2Context * const ic = avctx->priv_data;
201  static VLC_TYPE vlc_tables[1 << CODE_VLC_BITS][2];
202 
204  ic->avctx = avctx;
205 
206  avctx->pix_fmt= AV_PIX_FMT_YUV410P;
207 
208  ir2_vlc.table = vlc_tables;
209  ir2_vlc.table_allocated = 1 << CODE_VLC_BITS;
210 #ifdef BITSTREAM_READER_LE
211  init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
212  &ir2_codes[0][1], 4, 2,
214 #else
215  init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
216  &ir2_codes[0][1], 4, 2,
217  &ir2_codes[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
218 #endif
219 
220  return 0;
221 }
222 
224  Ir2Context * const ic = avctx->priv_data;
225  AVFrame *pic = &ic->picture;
226 
227  if (pic->data[0])
228  avctx->release_buffer(avctx, pic);
229 
230  return 0;
231 }
232 
234  .name = "indeo2",
235  .type = AVMEDIA_TYPE_VIDEO,
236  .id = AV_CODEC_ID_INDEO2,
237  .priv_data_size = sizeof(Ir2Context),
241  .capabilities = CODEC_CAP_DR1,
242  .long_name = NULL_IF_CONFIG_SMALL("Intel Indeo 2"),
243 };