FFmpeg
tiertexseqv.c
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1 /*
2  * Tiertex Limited SEQ Video Decoder
3  * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
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  * Tiertex Limited SEQ video decoder
25  */
26 
27 #define BITSTREAM_READER_LE
28 #include "avcodec.h"
29 #include "get_bits.h"
30 #include "internal.h"
31 
32 
33 typedef struct SeqVideoContext {
37 
38 
39 static const unsigned char *seq_unpack_rle_block(const unsigned char *src,
40  const unsigned char *src_end,
41  unsigned char *dst, int dst_size)
42 {
43  int i, len, sz;
44  GetBitContext gb;
45  int code_table[64];
46 
47  /* get the rle codes */
48  init_get_bits(&gb, src, (src_end - src) * 8);
49  for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
50  if (get_bits_left(&gb) < 4)
51  return NULL;
52  code_table[i] = get_sbits(&gb, 4);
53  sz += FFABS(code_table[i]);
54  }
55  src += (get_bits_count(&gb) + 7) / 8;
56 
57  /* do the rle unpacking */
58  for (i = 0; i < 64 && dst_size > 0; i++) {
59  len = code_table[i];
60  if (len < 0) {
61  len = -len;
62  if (src_end - src < 1)
63  return NULL;
64  memset(dst, *src++, FFMIN(len, dst_size));
65  } else {
66  if (src_end - src < len)
67  return NULL;
68  memcpy(dst, src, FFMIN(len, dst_size));
69  src += len;
70  }
71  dst += len;
72  dst_size -= len;
73  }
74  return src;
75 }
76 
77 static const unsigned char *seq_decode_op1(SeqVideoContext *seq,
78  const unsigned char *src,
79  const unsigned char *src_end,
80  unsigned char *dst)
81 {
82  const unsigned char *color_table;
83  int b, i, len, bits;
84  GetBitContext gb;
85  unsigned char block[8 * 8];
86 
87  if (src_end - src < 1)
88  return NULL;
89  len = *src++;
90  if (len & 0x80) {
91  switch (len & 3) {
92  case 1:
93  src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
94  for (b = 0; b < 8; b++) {
95  memcpy(dst, &block[b * 8], 8);
96  dst += seq->frame->linesize[0];
97  }
98  break;
99  case 2:
100  src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
101  for (i = 0; i < 8; i++) {
102  for (b = 0; b < 8; b++)
103  dst[b * seq->frame->linesize[0]] = block[i * 8 + b];
104  ++dst;
105  }
106  break;
107  }
108  } else {
109  if (len <= 0)
110  return NULL;
111  bits = ff_log2_tab[len - 1] + 1;
112  if (src_end - src < len + 8 * bits)
113  return NULL;
114  color_table = src;
115  src += len;
116  init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
117  for (b = 0; b < 8; b++) {
118  for (i = 0; i < 8; i++)
119  dst[i] = color_table[get_bits(&gb, bits)];
120  dst += seq->frame->linesize[0];
121  }
122  }
123 
124  return src;
125 }
126 
127 static const unsigned char *seq_decode_op2(SeqVideoContext *seq,
128  const unsigned char *src,
129  const unsigned char *src_end,
130  unsigned char *dst)
131 {
132  int i;
133 
134  if (src_end - src < 8 * 8)
135  return NULL;
136 
137  for (i = 0; i < 8; i++) {
138  memcpy(dst, src, 8);
139  src += 8;
140  dst += seq->frame->linesize[0];
141  }
142 
143  return src;
144 }
145 
146 static const unsigned char *seq_decode_op3(SeqVideoContext *seq,
147  const unsigned char *src,
148  const unsigned char *src_end,
149  unsigned char *dst)
150 {
151  int pos, offset;
152 
153  do {
154  if (src_end - src < 2)
155  return NULL;
156  pos = *src++;
157  offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7);
158  dst[offset] = *src++;
159  } while (!(pos & 0x80));
160 
161  return src;
162 }
163 
164 static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
165 {
166  const unsigned char *data_end = data + data_size;
167  GetBitContext gb;
168  int flags, i, j, x, y, op;
169  unsigned char c[3];
170  unsigned char *dst;
171  uint32_t *palette;
172 
173  flags = *data++;
174 
175  if (flags & 1) {
176  palette = (uint32_t *)seq->frame->data[1];
177  if (data_end - data < 256 * 3)
178  return AVERROR_INVALIDDATA;
179  for (i = 0; i < 256; i++) {
180  for (j = 0; j < 3; j++, data++)
181  c[j] = (*data << 2) | (*data >> 4);
182  palette[i] = 0xFFU << 24 | AV_RB24(c);
183  }
184  seq->frame->palette_has_changed = 1;
185  }
186 
187  if (flags & 2) {
188  if (data_end - data < 128)
189  return AVERROR_INVALIDDATA;
190  init_get_bits(&gb, data, 128 * 8); data += 128;
191  for (y = 0; y < 128; y += 8)
192  for (x = 0; x < 256; x += 8) {
193  dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x];
194  op = get_bits(&gb, 2);
195  switch (op) {
196  case 1:
197  data = seq_decode_op1(seq, data, data_end, dst);
198  break;
199  case 2:
200  data = seq_decode_op2(seq, data, data_end, dst);
201  break;
202  case 3:
203  data = seq_decode_op3(seq, data, data_end, dst);
204  break;
205  }
206  if (!data)
207  return AVERROR_INVALIDDATA;
208  }
209  }
210  return 0;
211 }
212 
214 {
215  SeqVideoContext *seq = avctx->priv_data;
216  int ret;
217 
218  seq->avctx = avctx;
219  avctx->pix_fmt = AV_PIX_FMT_PAL8;
220 
221  ret = ff_set_dimensions(avctx, 256, 128);
222  if (ret < 0)
223  return ret;
224 
225  seq->frame = av_frame_alloc();
226  if (!seq->frame)
227  return AVERROR(ENOMEM);
228 
229  return 0;
230 }
231 
233  void *data, int *got_frame,
234  AVPacket *avpkt)
235 {
236  const uint8_t *buf = avpkt->data;
237  int buf_size = avpkt->size;
238  int ret;
239 
240  SeqVideoContext *seq = avctx->priv_data;
241 
242  if ((ret = ff_reget_buffer(avctx, seq->frame, 0)) < 0)
243  return ret;
244 
245  if (seqvideo_decode(seq, buf, buf_size))
246  return AVERROR_INVALIDDATA;
247 
248  if ((ret = av_frame_ref(data, seq->frame)) < 0)
249  return ret;
250  *got_frame = 1;
251 
252  return buf_size;
253 }
254 
256 {
257  SeqVideoContext *seq = avctx->priv_data;
258 
259  av_frame_free(&seq->frame);
260 
261  return 0;
262 }
263 
265  .name = "tiertexseqvideo",
266  .long_name = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"),
267  .type = AVMEDIA_TYPE_VIDEO,
269  .priv_data_size = sizeof(SeqVideoContext),
271  .close = seqvideo_decode_end,
273  .capabilities = AV_CODEC_CAP_DR1,
274 };
#define NULL
Definition: coverity.c:32
#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:295
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:104
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
Definition: tiertexseqv.c:255
static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
Definition: tiertexseqv.c:213
AVFrame * frame
Definition: tiertexseqv.c:35
int size
Definition: avcodec.h:1481
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1778
static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
Definition: tiertexseqv.c:164
#define src
Definition: vp8dsp.c:254
AVCodec.
Definition: avcodec.h:3484
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:359
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
AVCodecContext * avctx
Definition: tiertexseqv.c:34
The exact code depends on how similar the blocks are and how related they are to the block
uint8_t
#define av_cold
Definition: attributes.h:82
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:189
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:443
uint8_t * data
Definition: avcodec.h:1480
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:219
bitstream reader API header.
#define U(x)
Definition: vp56_arith.h:37
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:849
static const unsigned char * seq_unpack_rle_block(const unsigned char *src, const unsigned char *src_end, unsigned char *dst, int dst_size)
Definition: tiertexseqv.c:39
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
static const ColorEntry color_table[]
Definition: xpmdec.c:50
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available...
Definition: decode.c:2010
const char * name
Name of the codec implementation.
Definition: avcodec.h:3491
uint8_t bits
Definition: vp3data.h:202
static const unsigned char * seq_decode_op3(SeqVideoContext *seq, const unsigned char *src, const unsigned char *src_end, unsigned char *dst)
Definition: tiertexseqv.c:146
#define b
Definition: input.c:41
#define FFMIN(a, b)
Definition: common.h:96
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
static const unsigned char * seq_decode_op1(SeqVideoContext *seq, const unsigned char *src, const unsigned char *src_end, unsigned char *dst)
Definition: tiertexseqv.c:77
const uint8_t ff_log2_tab[256]
Definition: log2_tab.c:23
if(ret)
Libavcodec external API header.
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:87
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
main external API structure.
Definition: avcodec.h:1568
void * buf
Definition: avisynth_c.h:766
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:659
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:452
#define flags(name, subs,...)
Definition: cbs_av1.c:561
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
static int op(uint8_t **dst, const uint8_t *dst_end, GetByteContext *gb, int pixel, int count, int *x, int width, int linesize)
Perform decode operation.
Definition: anm.c:78
common internal api header.
static int seqvideo_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: tiertexseqv.c:232
static const unsigned char * seq_decode_op2(SeqVideoContext *seq, const unsigned char *src, const unsigned char *src_end, unsigned char *dst)
Definition: tiertexseqv.c:127
void * priv_data
Definition: avcodec.h:1595
int len
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
This structure stores compressed data.
Definition: avcodec.h:1457
AVCodec ff_tiertexseqvideo_decoder
Definition: tiertexseqv.c:264
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:984