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/mem.h"
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "codec_internal.h"
33 #include "decode.h"
34 
35 typedef struct BFIContext {
36  uint8_t *dst;
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 {
54  int buf_size = avpkt->size;
55  BFIContext *bfi = avctx->priv_data;
56  uint8_t *dst = bfi->dst;
57  uint8_t *src, *dst_offset, colour1, colour2;
58  uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
59  uint32_t *pal;
60  int i, j, ret, height = avctx->height;
61 
62  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
63  return ret;
64 
65  bytestream2_init(&g, avpkt->data, buf_size);
66 
67  /* Set frame parameters and palette, if necessary */
68  if (!avctx->frame_num) {
69  frame->pict_type = AV_PICTURE_TYPE_I;
70  frame->flags |= AV_FRAME_FLAG_KEY;
71  /* Setting the palette */
72  if (avctx->extradata_size > 768) {
73  av_log(avctx, AV_LOG_ERROR, "Palette is too large.\n");
74  return AVERROR_INVALIDDATA;
75  }
76  pal = (uint32_t *)frame->data[1];
77  for (i = 0; i < avctx->extradata_size / 3; i++) {
78  int shift = 16;
79  *pal = 0xFFU << 24;
80  for (j = 0; j < 3; j++, shift -= 8)
81  *pal += ((avctx->extradata[i * 3 + j] << 2) |
82  (avctx->extradata[i * 3 + j] >> 4)) << shift;
83  pal++;
84  }
85  memcpy(bfi->pal, frame->data[1], sizeof(bfi->pal));
86 #if FF_API_PALETTE_HAS_CHANGED
88  frame->palette_has_changed = 1;
90 #endif
91  } else {
92  frame->pict_type = AV_PICTURE_TYPE_P;
93  frame->flags &= ~AV_FRAME_FLAG_KEY;
94 #if FF_API_PALETTE_HAS_CHANGED
96  frame->palette_has_changed = 0;
98 #endif
99  memcpy(frame->data[1], bfi->pal, sizeof(bfi->pal));
100  }
101 
102  bytestream2_skip(&g, 4); // Unpacked size, not required.
103 
104  while (dst != frame_end) {
105  static const uint8_t lentab[4] = { 0, 2, 0, 1 };
106  unsigned int byte = bytestream2_get_byte(&g), av_uninit(offset);
107  unsigned int code = byte >> 6;
108  unsigned int length = byte & ~0xC0;
109 
110  if (!bytestream2_get_bytes_left(&g)) {
111  av_log(avctx, AV_LOG_ERROR,
112  "Input resolution larger than actual frame.\n");
113  return AVERROR_INVALIDDATA;
114  }
115 
116  /* Get length and offset (if required) */
117  if (length == 0) {
118  if (code == 1) {
119  length = bytestream2_get_byte(&g);
120  offset = bytestream2_get_le16(&g);
121  } else {
122  length = bytestream2_get_le16(&g);
123  if (code == 2 && length == 0)
124  break;
125  }
126  } else {
127  if (code == 1)
128  offset = bytestream2_get_byte(&g);
129  }
130 
131  /* Do boundary check */
132  if (dst + (length << lentab[code]) > frame_end)
133  break;
134 
135  switch (code) {
136  case 0: // normal chain
137  if (length >= bytestream2_get_bytes_left(&g)) {
138  av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
139  return AVERROR_INVALIDDATA;
140  }
141  bytestream2_get_buffer(&g, dst, length);
142  dst += length;
143  break;
144  case 1: // back chain
145  dst_offset = dst - offset;
146  length *= 4; // Convert dwords to bytes.
147  if (dst_offset < bfi->dst)
148  break;
149  while (length--)
150  *dst++ = *dst_offset++;
151  break;
152  case 2: // skip chain
153  dst += length;
154  break;
155  case 3: // fill chain
156  colour1 = bytestream2_get_byte(&g);
157  colour2 = bytestream2_get_byte(&g);
158  while (length--) {
159  *dst++ = colour1;
160  *dst++ = colour2;
161  }
162  break;
163  }
164  }
165 
166  src = bfi->dst;
167  dst = frame->data[0];
168  while (height--) {
169  memcpy(dst, src, avctx->width);
170  src += avctx->width;
171  dst += frame->linesize[0];
172  }
173  *got_frame = 1;
174 
175  return buf_size;
176 }
177 
179 {
180  BFIContext *bfi = avctx->priv_data;
181  av_freep(&bfi->dst);
182  return 0;
183 }
184 
186  .p.name = "bfi",
187  CODEC_LONG_NAME("Brute Force & Ignorance"),
188  .p.type = AVMEDIA_TYPE_VIDEO,
189  .p.id = AV_CODEC_ID_BFI,
190  .priv_data_size = sizeof(BFIContext),
192  .close = bfi_decode_close,
194  .p.capabilities = AV_CODEC_CAP_DR1,
195 };
FF_ENABLE_DEPRECATION_WARNINGS
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:73
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:178
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:375
AVPacket::data
uint8_t * data
Definition: packet.h:524
FFCodec
Definition: codec_internal.h:127
BFIContext::pal
uint32_t pal[256]
Definition: bfi.c:37
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:626
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:524
BFIContext
Definition: bfi.c:35
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:287
g
const char * g
Definition: vf_curves.c:128
decode.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:272
ff_bfi_decoder
const FFCodec ff_bfi_decoder
Definition: bfi.c:185
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
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1554
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:366
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:525
codec_internal.h
shift
static int shift(int a, int b)
Definition: bonk.c:261
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:40
height
#define height
BFIContext::dst
uint8_t * dst
Definition: bfi.c:36
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:256
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:523
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:256
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
AVCodecContext::height
int height
Definition: avcodec.h:618
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:657
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:2030
av_uninit
#define av_uninit(x)
Definition: attributes.h:154
ret
ret
Definition: filter_design.txt:187
frame
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
Definition: filter_design.txt:264
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
mem.h
AVPacket
This structure stores compressed data.
Definition: packet.h:501
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:618
bytestream.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
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:50