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bfi.c
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1 /*
2  * Brute Force & Ignorance (BFI) video decoder
3  * Copyright (c) 2008 Sisir Koppaka
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  * @brief Brute Force & Ignorance (.bfi) video decoder
25  * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
26  * @see http://wiki.multimedia.cx/index.php?title=BFI
27  */
28 
29 #include "libavutil/common.h"
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "internal.h"
33 
34 typedef struct BFIContext {
37  uint32_t pal[256];
38 } BFIContext;
39 
41 {
42  BFIContext *bfi = avctx->priv_data;
43  avctx->pix_fmt = AV_PIX_FMT_PAL8;
44  bfi->dst = av_mallocz(avctx->width * avctx->height);
45  if (!bfi->dst)
46  return AVERROR(ENOMEM);
47  return 0;
48 }
49 
50 static int bfi_decode_frame(AVCodecContext *avctx, void *data,
51  int *got_frame, AVPacket *avpkt)
52 {
53  AVFrame *frame = data;
55  int buf_size = avpkt->size;
56  BFIContext *bfi = avctx->priv_data;
57  uint8_t *dst = bfi->dst;
58  uint8_t *src, *dst_offset, colour1, colour2;
59  uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
60  uint32_t *pal;
61  int i, j, ret, height = avctx->height;
62 
63  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
64  return ret;
65 
66  bytestream2_init(&g, avpkt->data, buf_size);
67 
68  /* Set frame parameters and palette, if necessary */
69  if (!avctx->frame_number) {
71  frame->key_frame = 1;
72  /* Setting the palette */
73  if (avctx->extradata_size > 768) {
74  av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
75  return AVERROR_INVALIDDATA;
76  }
77  pal = (uint32_t *)frame->data[1];
78  for (i = 0; i < avctx->extradata_size / 3; i++) {
79  int shift = 16;
80  *pal = 0xFFU << 24;
81  for (j = 0; j < 3; j++, shift -= 8)
82  *pal += ((avctx->extradata[i * 3 + j] << 2) |
83  (avctx->extradata[i * 3 + j] >> 4)) << shift;
84  pal++;
85  }
86  memcpy(bfi->pal, frame->data[1], sizeof(bfi->pal));
87  frame->palette_has_changed = 1;
88  } else {
90  frame->key_frame = 0;
91  frame->palette_has_changed = 0;
92  memcpy(frame->data[1], bfi->pal, sizeof(bfi->pal));
93  }
94 
95  bytestream2_skip(&g, 4); // Unpacked size, not required.
96 
97  while (dst != frame_end) {
98  static const uint8_t lentab[4] = { 0, 2, 0, 1 };
99  unsigned int byte = bytestream2_get_byte(&g), av_uninit(offset);
100  unsigned int code = byte >> 6;
101  unsigned int length = byte & ~0xC0;
102 
103  if (!bytestream2_get_bytes_left(&g)) {
104  av_log(avctx, AV_LOG_ERROR,
105  "Input resolution larger than actual frame.\n");
106  return AVERROR_INVALIDDATA;
107  }
108 
109  /* Get length and offset (if required) */
110  if (length == 0) {
111  if (code == 1) {
112  length = bytestream2_get_byte(&g);
113  offset = bytestream2_get_le16(&g);
114  } else {
115  length = bytestream2_get_le16(&g);
116  if (code == 2 && length == 0)
117  break;
118  }
119  } else {
120  if (code == 1)
121  offset = bytestream2_get_byte(&g);
122  }
123 
124  /* Do boundary check */
125  if (dst + (length << lentab[code]) > frame_end)
126  break;
127 
128  switch (code) {
129  case 0: // normal chain
130  if (length >= bytestream2_get_bytes_left(&g)) {
131  av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
132  return AVERROR_INVALIDDATA;
133  }
134  bytestream2_get_buffer(&g, dst, length);
135  dst += length;
136  break;
137  case 1: // back chain
138  dst_offset = dst - offset;
139  length *= 4; // Convert dwords to bytes.
140  if (dst_offset < bfi->dst)
141  break;
142  while (length--)
143  *dst++ = *dst_offset++;
144  break;
145  case 2: // skip chain
146  dst += length;
147  break;
148  case 3: // fill chain
149  colour1 = bytestream2_get_byte(&g);
150  colour2 = bytestream2_get_byte(&g);
151  while (length--) {
152  *dst++ = colour1;
153  *dst++ = colour2;
154  }
155  break;
156  }
157  }
158 
159  src = bfi->dst;
160  dst = frame->data[0];
161  while (height--) {
162  memcpy(dst, src, avctx->width);
163  src += avctx->width;
164  dst += frame->linesize[0];
165  }
166  *got_frame = 1;
167 
168  return buf_size;
169 }
170 
172 {
173  BFIContext *bfi = avctx->priv_data;
174  av_freep(&bfi->dst);
175  return 0;
176 }
177 
179  .name = "bfi",
180  .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
181  .type = AVMEDIA_TYPE_VIDEO,
182  .id = AV_CODEC_ID_BFI,
183  .priv_data_size = sizeof(BFIContext),
185  .close = bfi_decode_close,
187  .capabilities = AV_CODEC_CAP_DR1,
188 };
#define NULL
Definition: coverity.c:32
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static int shift(int a, int b)
Definition: sonic.c:82
This structure describes decoded (raw) audio or video data.
Definition: frame.h:184
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
const char * g
Definition: vf_curves.c:112
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1589
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1885
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
Definition: bfi.c:34
AVCodec.
Definition: avcodec.h:3559
AVCodec ff_bfi_decoder
Definition: bfi.c:178
uint8_t
#define av_cold
Definition: attributes.h:82
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:73
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1772
static AVFrame * frame
#define height
uint8_t * data
Definition: avcodec.h:1588
#define av_log(a,...)
#define U(x)
Definition: vp56_arith.h:37
uint32_t pal[256]
Definition: bfi.c:37
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define AVERROR(e)
Definition: error.h:43
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:164
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:263
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
GLsizei GLsizei * length
Definition: opengl_enc.c:115
const char * name
Name of the codec implementation.
Definition: avcodec.h:3566
uint8_t * dst
Definition: bfi.c:36
static const uint8_t offset[127][2]
Definition: vf_spp.c:92
static void frame_end(MpegEncContext *s)
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:258
static av_cold int bfi_decode_close(AVCodecContext *avctx)
Definition: bfi.c:171
int width
picture width / height.
Definition: avcodec.h:1844
#define src
Definition: vp9dsp.c:530
Libavcodec external API header.
AVCodecContext * avctx
Definition: bfi.c:35
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_WB24 unsigned int_TMPL AV_WB16 unsigned int_TMPL byte
Definition: bytestream.h:87
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:215
static av_cold int bfi_decode_init(AVCodecContext *avctx)
Definition: bfi.c:40
main external API structure.
Definition: avcodec.h:1657
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:928
int extradata_size
Definition: avcodec.h:1773
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:328
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:198
static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
Definition: ccaption_dec.c:752
common internal api header.
common internal and external API header
static int bfi_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: bfi.c:50
void * priv_data
Definition: avcodec.h:1699
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:253
#define av_uninit(x)
Definition: attributes.h:149
int frame_number
Frame counter, set by libavcodec.
Definition: avcodec.h:2449
#define av_freep(p)
This structure stores compressed data.
Definition: avcodec.h:1565
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:252
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:956
for(j=16;j >0;--j)
Predicted.
Definition: avutil.h:267