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 "codec_internal.h"
30 #include "decode.h"
31 #include "get_bits.h"
32 
33 
34 typedef struct SeqVideoContext {
38 
39 
40 static const unsigned char *seq_unpack_rle_block(const unsigned char *src,
41  const unsigned char *src_end,
42  unsigned char *dst, int dst_size)
43 {
44  int i, len, sz;
45  GetBitContext gb;
46  int code_table[64];
47 
48  /* get the rle codes */
49  init_get_bits(&gb, src, (src_end - src) * 8);
50  for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
51  if (get_bits_left(&gb) < 4)
52  return NULL;
53  code_table[i] = get_sbits(&gb, 4);
54  sz += FFABS(code_table[i]);
55  }
56  src += (get_bits_count(&gb) + 7) / 8;
57 
58  /* do the rle unpacking */
59  for (i = 0; i < 64 && dst_size > 0; i++) {
60  len = code_table[i];
61  if (len < 0) {
62  len = -len;
63  if (src_end - src < 1)
64  return NULL;
65  memset(dst, *src++, FFMIN(len, dst_size));
66  } else {
67  if (src_end - src < len)
68  return NULL;
69  memcpy(dst, src, FFMIN(len, dst_size));
70  src += len;
71  }
72  dst += len;
73  dst_size -= len;
74  }
75  return src;
76 }
77 
78 static const unsigned char *seq_decode_op1(SeqVideoContext *seq,
79  const unsigned char *src,
80  const unsigned char *src_end,
81  unsigned char *dst)
82 {
83  const unsigned char *color_table;
84  int b, i, len, bits;
85  GetBitContext gb;
86  unsigned char block[8 * 8];
87 
88  if (src_end - src < 1)
89  return NULL;
90  len = *src++;
91  if (len & 0x80) {
92  switch (len & 3) {
93  case 1:
94  src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
95  for (b = 0; b < 8; b++) {
96  memcpy(dst, &block[b * 8], 8);
97  dst += seq->frame->linesize[0];
98  }
99  break;
100  case 2:
101  src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
102  for (i = 0; i < 8; i++) {
103  for (b = 0; b < 8; b++)
104  dst[b * seq->frame->linesize[0]] = block[i * 8 + b];
105  ++dst;
106  }
107  break;
108  }
109  } else {
110  if (len <= 0)
111  return NULL;
112  bits = ff_log2_tab[len - 1] + 1;
113  if (src_end - src < len + 8 * bits)
114  return NULL;
115  color_table = src;
116  src += len;
117  init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
118  for (b = 0; b < 8; b++) {
119  for (i = 0; i < 8; i++)
120  dst[i] = color_table[get_bits(&gb, bits)];
121  dst += seq->frame->linesize[0];
122  }
123  }
124 
125  return src;
126 }
127 
128 static const unsigned char *seq_decode_op2(SeqVideoContext *seq,
129  const unsigned char *src,
130  const unsigned char *src_end,
131  unsigned char *dst)
132 {
133  int i;
134 
135  if (src_end - src < 8 * 8)
136  return NULL;
137 
138  for (i = 0; i < 8; i++) {
139  memcpy(dst, src, 8);
140  src += 8;
141  dst += seq->frame->linesize[0];
142  }
143 
144  return src;
145 }
146 
147 static const unsigned char *seq_decode_op3(SeqVideoContext *seq,
148  const unsigned char *src,
149  const unsigned char *src_end,
150  unsigned char *dst)
151 {
152  int pos, offset;
153 
154  do {
155  if (src_end - src < 2)
156  return NULL;
157  pos = *src++;
158  offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7);
159  dst[offset] = *src++;
160  } while (!(pos & 0x80));
161 
162  return src;
163 }
164 
165 static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
166 {
167  const unsigned char *data_end = data + data_size;
168  GetBitContext gb;
169  int flags, i, j, x, y, op;
170  unsigned char c[3];
171  unsigned char *dst;
172  uint32_t *palette;
173 
174  flags = *data++;
175 
176  if (flags & 1) {
177  palette = (uint32_t *)seq->frame->data[1];
178  if (data_end - data < 256 * 3)
179  return AVERROR_INVALIDDATA;
180  for (i = 0; i < 256; i++) {
181  for (j = 0; j < 3; j++, data++)
182  c[j] = (*data << 2) | (*data >> 4);
183  palette[i] = 0xFFU << 24 | AV_RB24(c);
184  }
185  seq->frame->palette_has_changed = 1;
186  }
187 
188  if (flags & 2) {
189  if (data_end - data < 128)
190  return AVERROR_INVALIDDATA;
191  init_get_bits(&gb, data, 128 * 8); data += 128;
192  for (y = 0; y < 128; y += 8)
193  for (x = 0; x < 256; x += 8) {
194  dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x];
195  op = get_bits(&gb, 2);
196  switch (op) {
197  case 1:
198  data = seq_decode_op1(seq, data, data_end, dst);
199  break;
200  case 2:
201  data = seq_decode_op2(seq, data, data_end, dst);
202  break;
203  case 3:
204  data = seq_decode_op3(seq, data, data_end, dst);
205  break;
206  }
207  if (!data)
208  return AVERROR_INVALIDDATA;
209  }
210  }
211  return 0;
212 }
213 
215 {
216  SeqVideoContext *seq = avctx->priv_data;
217  int ret;
218 
219  seq->avctx = avctx;
220  avctx->pix_fmt = AV_PIX_FMT_PAL8;
221 
222  ret = ff_set_dimensions(avctx, 256, 128);
223  if (ret < 0)
224  return ret;
225 
226  seq->frame = av_frame_alloc();
227  if (!seq->frame)
228  return AVERROR(ENOMEM);
229 
230  return 0;
231 }
232 
233 static int seqvideo_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
234  int *got_frame, 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(rframe, 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  .p.name = "tiertexseqvideo",
266  CODEC_LONG_NAME("Tiertex Limited SEQ video"),
267  .p.type = AVMEDIA_TYPE_VIDEO,
269  .priv_data_size = sizeof(SeqVideoContext),
271  .close = seqvideo_decode_end,
273  .p.capabilities = AV_CODEC_CAP_DR1,
274 };
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:839
AVERROR
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
SeqVideoContext
Definition: tiertexseqv.c:34
get_bits_count
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:219
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:116
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AVPacket::data
uint8_t * data
Definition: packet.h:374
b
#define b
Definition: input.c:41
data
const char data[16]
Definition: mxf.c:146
FFCodec
Definition: codec_internal.h:119
seqvideo_decode_end
static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
Definition: tiertexseqv.c:255
SeqVideoContext::frame
AVFrame * frame
Definition: tiertexseqv.c:36
ff_set_dimensions
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:91
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:649
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:346
init
static int init
Definition: av_tx.c:47
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:123
GetBitContext
Definition: get_bits.h:61
SeqVideoContext::avctx
AVCodecContext * avctx
Definition: tiertexseqv.c:35
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:104
av_cold
#define av_cold
Definition: attributes.h:90
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:298
op
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:76
bits
uint8_t bits
Definition: vp3data.h:141
get_sbits
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:359
AV_CODEC_ID_TIERTEXSEQVIDEO
@ AV_CODEC_ID_TIERTEXSEQVIDEO
Definition: codec_id.h:147
decode.h
get_bits.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:264
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:64
if
if(ret)
Definition: filter_design.txt:179
NULL
#define NULL
Definition: coverity.c:32
c
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
ff_log2_tab
const uint8_t ff_log2_tab[256]
Definition: log2_tab.c:23
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:375
av_frame_ref
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:353
codec_internal.h
offset
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
Definition: writing_filters.txt:86
seqvideo_decode_init
static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
Definition: tiertexseqv.c:214
seq_unpack_rle_block
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:40
seq_decode_op1
static const unsigned char * seq_decode_op1(SeqVideoContext *seq, const unsigned char *src, const unsigned char *src_end, unsigned char *dst)
Definition: tiertexseqv.c:78
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
len
int len
Definition: vorbis_enc_data.h:426
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
avcodec.h
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
ff_reget_buffer
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:1568
ret
ret
Definition: filter_design.txt:187
seq_decode_op3
static const unsigned char * seq_decode_op3(SeqVideoContext *seq, const unsigned char *src, const unsigned char *src_end, unsigned char *dst)
Definition: tiertexseqv.c:147
seq_decode_op2
static const unsigned char * seq_decode_op2(SeqVideoContext *seq, const unsigned char *src, const unsigned char *src_end, unsigned char *dst)
Definition: tiertexseqv.c:128
pos
unsigned int pos
Definition: spdifenc.c:412
U
#define U(x)
Definition: vpx_arith.h:37
seqvideo_decode
static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
Definition: tiertexseqv.c:165
AVCodecContext
main external API structure.
Definition: avcodec.h:398
AVFrame::palette_has_changed
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:487
ff_tiertexseqvideo_decoder
const FFCodec ff_tiertexseqvideo_decoder
Definition: tiertexseqv.c:264
seqvideo_decode_frame
static int seqvideo_decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)
Definition: tiertexseqv.c:233
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVPacket
This structure stores compressed data.
Definition: packet.h:351
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:425
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:370
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AV_RB24
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:97
color_table
static const ColorEntry color_table[]
Definition: xpmdec.c:50