FFmpeg
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 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  * id Quake II Cin Video Decoder by Dr. Tim Ferguson
25  * For more information about the id CIN format, visit:
26  * http://www.csse.monash.edu.au/~timf/
27  *
28  * This video decoder outputs PAL8 colorspace data. Interacting with this
29  * decoder is a little involved. During initialization, the demuxer must
30  * transmit the 65536-byte Huffman table(s) to the decoder via extradata.
31  * Then, whenever a palette change is encountered while demuxing the file,
32  * the demuxer must use the same extradata space to transmit an
33  * AVPaletteControl structure.
34  *
35  * id CIN video is purely Huffman-coded, intraframe-only codec. It achieves
36  * a little more compression by exploiting the fact that adjacent pixels
37  * tend to be similar.
38  *
39  * Note that this decoder could use libavcodec's optimized VLC facilities
40  * rather than naive, tree-based Huffman decoding. However, there are 256
41  * Huffman tables. Plus, the VLC bit coding order is right -> left instead
42  * or left -> right, so all of the bits would have to be reversed. Further,
43  * the original Quake II implementation likely used a similar naive
44  * decoding algorithm and it worked fine on much lower spec machines.
45  */
46 
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 hnode {
60  int count;
61  unsigned char used;
62  int children[2];
63 } hnode;
64 
65 typedef struct IdcinContext {
66 
68 
69  const unsigned char *buf;
70  int size;
71 
72  hnode huff_nodes[256][HUF_TOKENS*2];
73  int num_huff_nodes[256];
74 
75  uint32_t pal[256];
76 } IdcinContext;
77 
78 /**
79  * Find the lowest probability node in a Huffman table, and mark it as
80  * being assigned to a higher probability.
81  * @return the node index of the lowest unused node, or -1 if all nodes
82  * are used.
83  */
84 static int huff_smallest_node(hnode *hnodes, int num_hnodes) {
85  int i;
86  int best, best_node;
87 
88  best = 99999999;
89  best_node = -1;
90  for(i = 0; i < num_hnodes; i++) {
91  if(hnodes[i].used)
92  continue;
93  if(!hnodes[i].count)
94  continue;
95  if(hnodes[i].count < best) {
96  best = hnodes[i].count;
97  best_node = i;
98  }
99  }
100 
101  if(best_node == -1)
102  return -1;
103  hnodes[best_node].used = 1;
104  return best_node;
105 }
106 
107 /*
108  * Build the Huffman tree using the generated/loaded probabilities histogram.
109  *
110  * On completion:
111  * huff_nodes[prev][i < HUF_TOKENS] - are the nodes at the base of the tree.
112  * huff_nodes[prev][i >= HUF_TOKENS] - are used to construct the tree.
113  * num_huff_nodes[prev] - contains the index to the root node of the tree.
114  * That is: huff_nodes[prev][num_huff_nodes[prev]] is the root node.
115  */
116 static av_cold void huff_build_tree(IdcinContext *s, int prev) {
117  hnode *node, *hnodes;
118  int num_hnodes, i;
119 
120  num_hnodes = HUF_TOKENS;
121  hnodes = s->huff_nodes[prev];
122  for(i = 0; i < HUF_TOKENS * 2; i++)
123  hnodes[i].used = 0;
124 
125  while (1) {
126  node = &hnodes[num_hnodes]; /* next free node */
127 
128  /* pick two lowest counts */
129  node->children[0] = huff_smallest_node(hnodes, num_hnodes);
130  if(node->children[0] == -1)
131  break; /* reached the root node */
132 
133  node->children[1] = huff_smallest_node(hnodes, num_hnodes);
134  if(node->children[1] == -1)
135  break; /* reached the root node */
136 
137  /* combine nodes probability for new node */
138  node->count = hnodes[node->children[0]].count +
139  hnodes[node->children[1]].count;
140  num_hnodes++;
141  }
142 
143  s->num_huff_nodes[prev] = num_hnodes - 1;
144 }
145 
147 {
148  IdcinContext *s = avctx->priv_data;
149  int i, j, histogram_index = 0;
150  unsigned char *histograms;
151 
152  s->avctx = avctx;
153  avctx->pix_fmt = AV_PIX_FMT_PAL8;
154 
155  /* make sure the Huffman tables make it */
157  av_log(s->avctx, AV_LOG_ERROR, " id CIN video: expected extradata size of %d\n", HUFFMAN_TABLE_SIZE);
158  return -1;
159  }
160 
161  /* build the 256 Huffman decode trees */
162  histograms = (unsigned char *)s->avctx->extradata;
163  for (i = 0; i < 256; i++) {
164  for(j = 0; j < HUF_TOKENS; j++)
165  s->huff_nodes[i][j].count = histograms[histogram_index++];
166  huff_build_tree(s, i);
167  }
168 
169  return 0;
170 }
171 
173 {
174  hnode *hnodes;
175  long x, y;
176  int prev;
177  unsigned char v = 0;
178  int bit_pos, node_num, dat_pos;
179 
180  prev = bit_pos = dat_pos = 0;
181  for (y = 0; y < (frame->linesize[0] * s->avctx->height);
182  y += frame->linesize[0]) {
183  for (x = y; x < y + s->avctx->width; x++) {
184  node_num = s->num_huff_nodes[prev];
185  hnodes = s->huff_nodes[prev];
186 
187  while(node_num >= HUF_TOKENS) {
188  if(!bit_pos) {
189  if(dat_pos >= s->size) {
190  av_log(s->avctx, AV_LOG_ERROR, "Huffman decode error.\n");
191  return -1;
192  }
193  bit_pos = 8;
194  v = s->buf[dat_pos++];
195  }
196 
197  node_num = hnodes[node_num].children[v & 0x01];
198  v = v >> 1;
199  bit_pos--;
200  }
201 
202  frame->data[0][x] = node_num;
203  prev = node_num;
204  }
205  }
206 
207  return 0;
208 }
209 
211  void *data, int *got_frame,
212  AVPacket *avpkt)
213 {
214  const uint8_t *buf = avpkt->data;
215  int buf_size = avpkt->size;
216  IdcinContext *s = avctx->priv_data;
217  int pal_size;
218  const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &pal_size);
219  AVFrame *frame = data;
220  int ret;
221 
222  s->buf = buf;
223  s->size = buf_size;
224 
225  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
226  return ret;
227 
228  if (idcin_decode_vlcs(s, frame))
229  return AVERROR_INVALIDDATA;
230 
231  if (pal && pal_size == AVPALETTE_SIZE) {
232  frame->palette_has_changed = 1;
233  memcpy(s->pal, pal, AVPALETTE_SIZE);
234  } else if (pal) {
235  av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", pal_size);
236  }
237  /* make the palette available on the way out */
238  memcpy(frame->data[1], s->pal, AVPALETTE_SIZE);
239 
240  *got_frame = 1;
241 
242  /* report that the buffer was completely consumed */
243  return buf_size;
244 }
245 
247  .name = "idcinvideo",
248  .long_name = NULL_IF_CONFIG_SMALL("id Quake II CIN video"),
249  .type = AVMEDIA_TYPE_VIDEO,
250  .id = AV_CODEC_ID_IDCIN,
251  .priv_data_size = sizeof(IdcinContext),
254  .capabilities = AV_CODEC_CAP_DR1,
255 };
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:268
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1478
static int idcin_decode_vlcs(IdcinContext *s, AVFrame *frame)
Definition: idcinvideo.c:172
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1775
AVCodec.
Definition: avcodec.h:3477
int num_huff_nodes[256]
Definition: idcinvideo.c:73
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:42
uint8_t
#define av_cold
Definition: attributes.h:82
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1666
AVCodec ff_idcin_decoder
Definition: idcinvideo.c:246
uint8_t * data
Definition: avcodec.h:1477
hnode huff_nodes[256][HUF_TOKENS *2]
Definition: idcinvideo.c:72
#define av_log(a,...)
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:260
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE bytes worth of palette...
Definition: avcodec.h:1190
static int huff_smallest_node(hnode *hnodes, int num_hnodes)
Find the lowest probability node in a Huffman table, and mark it as being assigned to a higher probab...
Definition: idcinvideo.c:84
uint8_t * av_packet_get_side_data(const AVPacket *pkt, enum AVPacketSideDataType type, int *size)
Get side information from packet.
Definition: avpacket.c:350
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
#define HUFFMAN_TABLE_SIZE
Definition: idcinvideo.c:55
const char * name
Name of the codec implementation.
Definition: avcodec.h:3484
GLsizei count
Definition: opengl_enc.c:108
common internal API header
int width
picture width / height.
Definition: avcodec.h:1738
int count
Definition: idcinvideo.c:60
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
#define s(width, name)
Definition: cbs_vp9.c:257
static av_cold void huff_build_tree(IdcinContext *s, int prev)
Definition: idcinvideo.c:116
const unsigned char * buf
Definition: idcinvideo.c:69
AVCodecContext * avctx
Definition: idcinvideo.c:67
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:299
main external API structure.
Definition: avcodec.h:1565
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1964
int children[2]
Definition: idcinvideo.c:62
void * buf
Definition: avisynth_c.h:766
int extradata_size
Definition: avcodec.h:1667
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:425
#define HUF_TOKENS
Definition: idcinvideo.c:56
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:282
common internal api header.
static av_cold int idcin_decode_init(AVCodecContext *avctx)
Definition: idcinvideo.c:146
void * priv_data
Definition: avcodec.h:1592
static int idcin_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: idcinvideo.c:210
uint32_t pal[256]
Definition: idcinvideo.c:75
unsigned char used
Definition: idcinvideo.c:61
This structure stores compressed data.
Definition: avcodec.h:1454
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:981
for(j=16;j >0;--j)