FFmpeg
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 
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(avctx, 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  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
189 };
#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:295
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
const char * g
Definition: vf_curves.c:115
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1481
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1778
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
Definition: bfi.c:34
#define src
Definition: vp8dsp.c:254
AVCodec.
Definition: avcodec.h:3492
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
AVCodec ff_bfi_decoder
Definition: bfi.c:178
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:40
uint8_t
#define av_cold
Definition: attributes.h:82
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
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1669
#define height
uint8_t * data
Definition: avcodec.h:1480
#define av_log(a,...)
#define U(x)
Definition: vp56_arith.h:37
uint32_t pal[256]
Definition: bfi.c:37
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
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:186
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:114
const char * name
Name of the codec implementation.
Definition: avcodec.h:3499
uint8_t * dst
Definition: bfi.c:36
static void frame_end(MpegEncContext *s)
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:378
static av_cold int bfi_decode_close(AVCodecContext *avctx)
Definition: bfi.c:171
int width
picture width / height.
Definition: avcodec.h:1741
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
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:326
static av_cold int bfi_decode_init(AVCodecContext *avctx)
Definition: bfi.c:40
main external API structure.
Definition: avcodec.h:1568
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1968
int extradata_size
Definition: avcodec.h:1670
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:452
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
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:1595
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:373
#define av_uninit(x)
Definition: attributes.h:148
int frame_number
Frame counter, set by libavcodec.
Definition: avcodec.h:2259
#define av_freep(p)
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
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:984
for(j=16;j >0;--j)
Predicted.
Definition: avutil.h:275