FFmpeg
bfi.c
Go to the documentation of this file.
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 "codec_internal.h"
33 #include "decode.h"
34 
35 typedef struct BFIContext {
37  uint8_t *dst;
38  uint32_t pal[256];
39 } BFIContext;
40 
42 {
43  BFIContext *bfi = avctx->priv_data;
44  avctx->pix_fmt = AV_PIX_FMT_PAL8;
45  bfi->dst = av_mallocz(avctx->width * avctx->height);
46  if (!bfi->dst)
47  return AVERROR(ENOMEM);
48  return 0;
49 }
50 
52  int *got_frame, AVPacket *avpkt)
53 {
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_num) {
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 #if FF_API_PALETTE_HAS_CHANGED
91 #endif
92  } else {
95 #if FF_API_PALETTE_HAS_CHANGED
99 #endif
100  memcpy(frame->data[1], bfi->pal, sizeof(bfi->pal));
101  }
102 
103  bytestream2_skip(&g, 4); // Unpacked size, not required.
104 
105  while (dst != frame_end) {
106  static const uint8_t lentab[4] = { 0, 2, 0, 1 };
107  unsigned int byte = bytestream2_get_byte(&g), av_uninit(offset);
108  unsigned int code = byte >> 6;
109  unsigned int length = byte & ~0xC0;
110 
111  if (!bytestream2_get_bytes_left(&g)) {
112  av_log(avctx, AV_LOG_ERROR,
113  "Input resolution larger than actual frame.\n");
114  return AVERROR_INVALIDDATA;
115  }
116 
117  /* Get length and offset (if required) */
118  if (length == 0) {
119  if (code == 1) {
120  length = bytestream2_get_byte(&g);
121  offset = bytestream2_get_le16(&g);
122  } else {
123  length = bytestream2_get_le16(&g);
124  if (code == 2 && length == 0)
125  break;
126  }
127  } else {
128  if (code == 1)
129  offset = bytestream2_get_byte(&g);
130  }
131 
132  /* Do boundary check */
133  if (dst + (length << lentab[code]) > frame_end)
134  break;
135 
136  switch (code) {
137  case 0: // normal chain
138  if (length >= bytestream2_get_bytes_left(&g)) {
139  av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
140  return AVERROR_INVALIDDATA;
141  }
142  bytestream2_get_buffer(&g, dst, length);
143  dst += length;
144  break;
145  case 1: // back chain
146  dst_offset = dst - offset;
147  length *= 4; // Convert dwords to bytes.
148  if (dst_offset < bfi->dst)
149  break;
150  while (length--)
151  *dst++ = *dst_offset++;
152  break;
153  case 2: // skip chain
154  dst += length;
155  break;
156  case 3: // fill chain
157  colour1 = bytestream2_get_byte(&g);
158  colour2 = bytestream2_get_byte(&g);
159  while (length--) {
160  *dst++ = colour1;
161  *dst++ = colour2;
162  }
163  break;
164  }
165  }
166 
167  src = bfi->dst;
168  dst = frame->data[0];
169  while (height--) {
170  memcpy(dst, src, avctx->width);
171  src += avctx->width;
172  dst += frame->linesize[0];
173  }
174  *got_frame = 1;
175 
176  return buf_size;
177 }
178 
180 {
181  BFIContext *bfi = avctx->priv_data;
182  av_freep(&bfi->dst);
183  return 0;
184 }
185 
187  .p.name = "bfi",
188  CODEC_LONG_NAME("Brute Force & Ignorance"),
189  .p.type = AVMEDIA_TYPE_VIDEO,
190  .p.id = AV_CODEC_ID_BFI,
191  .priv_data_size = sizeof(BFIContext),
193  .close = bfi_decode_close,
195  .p.capabilities = AV_CODEC_CAP_DR1,
196 };
FF_ENABLE_DEPRECATION_WARNINGS
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:73
AVFrame::palette_has_changed
attribute_deprecated int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:546
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
GetByteContext
Definition: bytestream.h:33
bfi_decode_close
static av_cold int bfi_decode_close(AVCodecContext *avctx)
Definition: bfi.c:179
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
AVPacket::data
uint8_t * data
Definition: packet.h:522
FFCodec
Definition: codec_internal.h:127
AVFrame::flags
int flags
Frame flags, a combination of AV_FRAME_FLAGS.
Definition: frame.h:649
BFIContext::pal
uint32_t pal[256]
Definition: bfi.c:38
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:361
bytestream2_skip
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
frame_end
static int64_t frame_end(const SyncQueue *sq, SyncQueueFrame frame, int nb_samples)
Compute the end timestamp of a frame.
Definition: sync_queue.c:128
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
AV_FRAME_FLAG_KEY
#define AV_FRAME_FLAG_KEY
A flag to mark frames that are keyframes.
Definition: frame.h:628
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:547
BFIContext
Definition: bfi.c:35
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:306
g
const char * g
Definition: vf_curves.c:127
decode.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:272
frame
static AVFrame * frame
Definition: demux_decode.c:54
ff_bfi_decoder
const FFCodec ff_bfi_decoder
Definition: bfi.c:186
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:279
bytestream2_get_buffer
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:267
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
BFIContext::avctx
AVCodecContext * avctx
Definition: bfi.c:36
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:442
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1618
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:365
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:523
codec_internal.h
shift
static int shift(int a, int b)
Definition: bonk.c:262
for
for(k=2;k<=8;++k)
Definition: h264pred_template.c:425
bfi_decode_init
static av_cold int bfi_decode_init(AVCodecContext *avctx)
Definition: bfi.c:41
height
#define height
BFIContext::dst
uint8_t * dst
Definition: bfi.c:37
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
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:255
code
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
Definition: filter_design.txt:178
AVCodecContext::extradata
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:546
common.h
av_mallocz
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:254
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
AVCodecContext::height
int height
Definition: avcodec.h:625
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:662
avcodec.h
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:84
AVCodecContext::frame_num
int64_t frame_num
Frame counter, set by libavcodec.
Definition: avcodec.h:2122
av_uninit
#define av_uninit(x)
Definition: attributes.h:154
ret
ret
Definition: filter_design.txt:187
U
#define U(x)
Definition: vpx_arith.h:37
AVCodecContext
main external API structure.
Definition: avcodec.h:445
AV_CODEC_ID_BFI
@ AV_CODEC_ID_BFI
Definition: codec_id.h:169
FF_DISABLE_DEPRECATION_WARNINGS
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:72
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:280
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVPacket
This structure stores compressed data.
Definition: packet.h:499
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:472
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:625
bytestream.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
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:385
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
bfi_decode_frame
static int bfi_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)
Definition: bfi.c:51