Libav
idcinvideo.c
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1 /*
2  * id Quake II CIN Video Decoder
3  * Copyright (C) 2003 the ffmpeg project
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 
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 
51 #include "avcodec.h"
52 #include "internal.h"
53 #include "libavutil/internal.h"
54 
55 #define HUFFMAN_TABLE_SIZE 64 * 1024
56 #define HUF_TOKENS 256
57 #define PALETTE_COUNT 256
58 
59 typedef struct
60 {
61  int count;
62  unsigned char used;
63  int children[2];
64 } hnode;
65 
66 typedef struct IdcinContext {
67 
69 
70  const unsigned char *buf;
71  int size;
72 
74  int num_huff_nodes[256];
75 
76  uint32_t pal[256];
77 } IdcinContext;
78 
79 /*
80  * Find the lowest probability node in a Huffman table, and mark it as
81  * being assigned to a higher probability.
82  * @return the node index of the lowest unused node, or -1 if all nodes
83  * are used.
84  */
85 static int huff_smallest_node(hnode *hnodes, int num_hnodes) {
86  int i;
87  int best, best_node;
88 
89  best = 99999999;
90  best_node = -1;
91  for(i = 0; i < num_hnodes; i++) {
92  if(hnodes[i].used)
93  continue;
94  if(!hnodes[i].count)
95  continue;
96  if(hnodes[i].count < best) {
97  best = hnodes[i].count;
98  best_node = i;
99  }
100  }
101 
102  if(best_node == -1)
103  return -1;
104  hnodes[best_node].used = 1;
105  return best_node;
106 }
107 
108 /*
109  * Build the Huffman tree using the generated/loaded probabilities histogram.
110  *
111  * On completion:
112  * huff_nodes[prev][i < HUF_TOKENS] - are the nodes at the base of the tree.
113  * huff_nodes[prev][i >= HUF_TOKENS] - are used to construct the tree.
114  * num_huff_nodes[prev] - contains the index to the root node of the tree.
115  * That is: huff_nodes[prev][num_huff_nodes[prev]] is the root node.
116  */
117 static av_cold void huff_build_tree(IdcinContext *s, int prev) {
118  hnode *node, *hnodes;
119  int num_hnodes, i;
120 
121  num_hnodes = HUF_TOKENS;
122  hnodes = s->huff_nodes[prev];
123  for(i = 0; i < HUF_TOKENS * 2; i++)
124  hnodes[i].used = 0;
125 
126  while (1) {
127  node = &hnodes[num_hnodes]; /* next free node */
128 
129  /* pick two lowest counts */
130  node->children[0] = huff_smallest_node(hnodes, num_hnodes);
131  if(node->children[0] == -1)
132  break; /* reached the root node */
133 
134  node->children[1] = huff_smallest_node(hnodes, num_hnodes);
135  if(node->children[1] == -1)
136  break; /* reached the root node */
137 
138  /* combine nodes probability for new node */
139  node->count = hnodes[node->children[0]].count +
140  hnodes[node->children[1]].count;
141  num_hnodes++;
142  }
143 
144  s->num_huff_nodes[prev] = num_hnodes - 1;
145 }
146 
148 {
149  IdcinContext *s = avctx->priv_data;
150  int i, j, histogram_index = 0;
151  unsigned char *histograms;
152 
153  s->avctx = avctx;
154  avctx->pix_fmt = AV_PIX_FMT_PAL8;
155 
156  /* make sure the Huffman tables make it */
158  av_log(s->avctx, AV_LOG_ERROR, " id CIN video: expected extradata size of %d\n", HUFFMAN_TABLE_SIZE);
159  return -1;
160  }
161 
162  /* build the 256 Huffman decode trees */
163  histograms = (unsigned char *)s->avctx->extradata;
164  for (i = 0; i < 256; i++) {
165  for(j = 0; j < HUF_TOKENS; j++)
166  s->huff_nodes[i][j].count = histograms[histogram_index++];
167  huff_build_tree(s, i);
168  }
169 
170  return 0;
171 }
172 
173 static void idcin_decode_vlcs(IdcinContext *s, AVFrame *frame)
174 {
175  hnode *hnodes;
176  long x, y;
177  int prev;
178  unsigned char v = 0;
179  int bit_pos, node_num, dat_pos;
180 
181  prev = bit_pos = dat_pos = 0;
182  for (y = 0; y < (frame->linesize[0] * s->avctx->height);
183  y += frame->linesize[0]) {
184  for (x = y; x < y + s->avctx->width; x++) {
185  node_num = s->num_huff_nodes[prev];
186  hnodes = s->huff_nodes[prev];
187 
188  while(node_num >= HUF_TOKENS) {
189  if(!bit_pos) {
190  if(dat_pos >= s->size) {
191  av_log(s->avctx, AV_LOG_ERROR, "Huffman decode error.\n");
192  return;
193  }
194  bit_pos = 8;
195  v = s->buf[dat_pos++];
196  }
197 
198  node_num = hnodes[node_num].children[v & 0x01];
199  v = v >> 1;
200  bit_pos--;
201  }
202 
203  frame->data[0][x] = node_num;
204  prev = node_num;
205  }
206  }
207 }
208 
210  void *data, int *got_frame,
211  AVPacket *avpkt)
212 {
213  const uint8_t *buf = avpkt->data;
214  int buf_size = avpkt->size;
215  IdcinContext *s = avctx->priv_data;
217  AVFrame *frame = data;
218  int ret;
219 
220  s->buf = buf;
221  s->size = buf_size;
222 
223  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
224  av_log(avctx, AV_LOG_ERROR, " id CIN Video: get_buffer() failed\n");
225  return ret;
226  }
227 
228  idcin_decode_vlcs(s, frame);
229 
230  if (pal) {
231  frame->palette_has_changed = 1;
232  memcpy(s->pal, pal, AVPALETTE_SIZE);
233  }
234  /* make the palette available on the way out */
235  memcpy(frame->data[1], s->pal, AVPALETTE_SIZE);
236 
237  *got_frame = 1;
238 
239  /* report that the buffer was completely consumed */
240  return buf_size;
241 }
242 
244  .name = "idcinvideo",
245  .long_name = NULL_IF_CONFIG_SMALL("id Quake II CIN video"),
246  .type = AVMEDIA_TYPE_VIDEO,
247  .id = AV_CODEC_ID_IDCIN,
248  .priv_data_size = sizeof(IdcinContext),
251  .capabilities = CODEC_CAP_DR1,
252 };
#define AVPALETTE_SIZE
Definition: avcodec.h:3051
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
int size
Definition: avcodec.h:974
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1270
AVCodec.
Definition: avcodec.h:2812
int num_huff_nodes[256]
Definition: idcinvideo.c:74
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:275
uint8_t
static void idcin_decode_vlcs(IdcinContext *s, AVFrame *frame)
Definition: idcinvideo.c:173
#define av_cold
Definition: attributes.h:66
8 bit with PIX_FMT_RGB32 palette
Definition: pixfmt.h:76
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1164
AVCodec ff_idcin_decoder
Definition: idcinvideo.c:243
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:684
const char data[16]
Definition: mxf.c:70
uint8_t * data
Definition: avcodec.h:973
hnode huff_nodes[256][HUF_TOKENS *2]
Definition: idcinvideo.c:73
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
static int huff_smallest_node(hnode *hnodes, int num_hnodes)
Definition: idcinvideo.c:85
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:145
#define HUFFMAN_TABLE_SIZE
Definition: idcinvideo.c:55
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
const char * name
Name of the codec implementation.
Definition: avcodec.h:2819
common internal API header
int width
picture width / height.
Definition: avcodec.h:1229
int count
Definition: idcinvideo.c:61
static av_cold void huff_build_tree(IdcinContext *s, int prev)
Definition: idcinvideo.c:117
const unsigned char * buf
Definition: idcinvideo.c:70
NULL
Definition: eval.c:55
AVCodecContext * avctx
Definition: idcinvideo.c:68
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:153
main external API structure.
Definition: avcodec.h:1050
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:621
int children[2]
Definition: idcinvideo.c:63
int extradata_size
Definition: avcodec.h:1165
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:330
#define HUF_TOKENS
Definition: idcinvideo.c:56
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
common internal api header.
static av_cold int idcin_decode_init(AVCodecContext *avctx)
Definition: idcinvideo.c:147
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:499
void * priv_data
Definition: avcodec.h:1092
static int idcin_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: idcinvideo.c:209
uint32_t pal[256]
Definition: idcinvideo.c:76
unsigned char used
Definition: idcinvideo.c:62
uint8_t * av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type, int *size)
Get side information from packet.
Definition: avpacket.c:287
This structure stores compressed data.
Definition: avcodec.h:950
for(j=16;j >0;--j)