FFmpeg
qpeg.c
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1 /*
2  * QPEG codec
3  * Copyright (c) 2004 Konstantin Shishkov
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  * QPEG codec.
25  */
26 
27 #include "avcodec.h"
28 #include "bytestream.h"
29 #include "codec_internal.h"
30 #include "decode.h"
31 
32 #include "libavutil/attributes.h"
33 
34 typedef struct QpegContext{
37  uint32_t pal[256];
39 } QpegContext;
40 
41 static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst,
42  int stride, int width, int height)
43 {
44  int i;
45  int code;
46  int c0, c1;
47  int run, copy;
48  int filled = 0;
49  int rows_to_go;
50 
51  rows_to_go = height;
52  height--;
53  dst = dst + height * stride;
54 
55  while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (rows_to_go > 0)) {
56  code = bytestream2_get_byte(&qctx->buffer);
57  run = copy = 0;
58  if(code == 0xFC) /* end-of-picture code */
59  break;
60  if(code >= 0xF8) { /* very long run */
61  c0 = bytestream2_get_byte(&qctx->buffer);
62  c1 = bytestream2_get_byte(&qctx->buffer);
63  run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2;
64  } else if (code >= 0xF0) { /* long run */
65  c0 = bytestream2_get_byte(&qctx->buffer);
66  run = ((code & 0xF) << 8) + c0 + 2;
67  } else if (code >= 0xE0) { /* short run */
68  run = (code & 0x1F) + 2;
69  } else if (code >= 0xC0) { /* very long copy */
70  c0 = bytestream2_get_byte(&qctx->buffer);
71  c1 = bytestream2_get_byte(&qctx->buffer);
72  copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1;
73  } else if (code >= 0x80) { /* long copy */
74  c0 = bytestream2_get_byte(&qctx->buffer);
75  copy = ((code & 0x7F) << 8) + c0 + 1;
76  } else { /* short copy */
77  copy = code + 1;
78  }
79 
80  /* perform actual run or copy */
81  if(run) {
82  int p;
83 
84  p = bytestream2_get_byte(&qctx->buffer);
85  for(i = 0; i < run; i++) {
86  int step = FFMIN(run - i, width - filled);
87  memset(dst+filled, p, step);
88  filled += step;
89  i += step - 1;
90  if (filled >= width) {
91  filled = 0;
92  dst -= stride;
93  rows_to_go--;
94  while (run - i > width && rows_to_go > 0) {
95  memset(dst, p, width);
96  dst -= stride;
97  rows_to_go--;
98  i += width;
99  }
100  if(rows_to_go <= 0)
101  break;
102  }
103  }
104  } else {
105  if (bytestream2_get_bytes_left(&qctx->buffer) < copy)
107  while (copy > 0) {
108  int step = FFMIN(copy, width - filled);
109  bytestream2_get_bufferu(&qctx->buffer, dst + filled, step);
110  filled += step;
111  copy -= step;
112  if (filled >= width) {
113  filled = 0;
114  dst -= stride;
115  rows_to_go--;
116  if(rows_to_go <= 0)
117  break;
118  }
119  }
120  }
121  }
122 }
123 
124 static const uint8_t qpeg_table_h[16] =
125  { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04};
126 static const uint8_t qpeg_table_w[16] =
127  { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04};
128 
129 /* Decodes delta frames */
130 static void av_noinline qpeg_decode_inter(QpegContext *qctx, uint8_t *dst,
131  int stride, int width, int height,
132  int delta, const uint8_t *ctable,
133  uint8_t *refdata)
134 {
135  int i, j;
136  int code;
137  int filled = 0;
138  int orig_height;
139 
140  if (refdata) {
141  /* copy prev frame */
142  for (i = 0; i < height; i++)
143  memcpy(dst + (i * stride), refdata + (i * stride), width);
144  } else {
145  refdata = dst;
146  }
147 
148  orig_height = height;
149  height--;
150  dst = dst + height * stride;
151 
152  while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) {
153  code = bytestream2_get_byte(&qctx->buffer);
154 
155  if(delta) {
156  /* motion compensation */
157  while(bytestream2_get_bytes_left(&qctx->buffer) > 0 && (code & 0xF0) == 0xF0) {
158  if(delta == 1) {
159  int me_idx;
160  int me_w, me_h, me_x, me_y;
161  uint8_t *me_plane;
162  int corr, val;
163 
164  /* get block size by index */
165  me_idx = code & 0xF;
166  me_w = qpeg_table_w[me_idx];
167  me_h = qpeg_table_h[me_idx];
168 
169  /* extract motion vector */
170  corr = bytestream2_get_byte(&qctx->buffer);
171 
172  val = corr >> 4;
173  if(val > 7)
174  val -= 16;
175  me_x = val;
176 
177  val = corr & 0xF;
178  if(val > 7)
179  val -= 16;
180  me_y = val;
181 
182  /* check motion vector */
183  if ((me_x + filled < 0) || (me_x + me_w + filled > width) ||
184  (height - me_y - me_h < 0) || (height - me_y >= orig_height) ||
185  (filled + me_w > width) || (height - me_h < 0))
186  av_log(qctx->avctx, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n",
187  me_x, me_y, me_w, me_h, filled, height);
188  else {
189  /* do motion compensation */
190  me_plane = refdata + (filled + me_x) + (height - me_y) * stride;
191  for(j = 0; j < me_h; j++) {
192  for(i = 0; i < me_w; i++)
193  dst[filled + i - (j * stride)] = me_plane[i - (j * stride)];
194  }
195  }
196  }
197  code = bytestream2_get_byte(&qctx->buffer);
198  }
199  }
200 
201  if(code == 0xE0) /* end-of-picture code */
202  break;
203  if(code > 0xE0) { /* run code: 0xE1..0xFF */
204  int p;
205 
206  code &= 0x1F;
207  p = bytestream2_get_byte(&qctx->buffer);
208  for(i = 0; i <= code; i++) {
209  dst[filled++] = p;
210  if(filled >= width) {
211  filled = 0;
212  dst -= stride;
213  height--;
214  if (height < 0)
215  break;
216  }
217  }
218  } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */
219  code &= 0x1F;
220 
221  if(code + 1 > bytestream2_get_bytes_left(&qctx->buffer))
222  break;
223 
224  for(i = 0; i <= code; i++) {
225  dst[filled++] = bytestream2_get_byte(&qctx->buffer);
226  if(filled >= width) {
227  filled = 0;
228  dst -= stride;
229  height--;
230  if (height < 0)
231  break;
232  }
233  }
234  } else if(code >= 0x80) { /* skip code: 0x80..0xBF */
235  int skip;
236 
237  code &= 0x3F;
238  /* codes 0x80 and 0x81 are actually escape codes,
239  skip value minus constant is in the next byte */
240  if(!code)
241  skip = bytestream2_get_byte(&qctx->buffer) + 64;
242  else if(code == 1)
243  skip = bytestream2_get_byte(&qctx->buffer) + 320;
244  else
245  skip = code;
246  filled += skip;
247  while( filled >= width) {
248  filled -= width;
249  dst -= stride;
250  height--;
251  if(height < 0)
252  break;
253  }
254  } else {
255  /* zero code treated as one-pixel skip */
256  if(code) {
257  dst[filled++] = ctable[code & 0x7F];
258  }
259  else
260  filled++;
261  if(filled >= width) {
262  filled = 0;
263  dst -= stride;
264  height--;
265  }
266  }
267  }
268 }
269 
270 static int decode_frame(AVCodecContext *avctx, AVFrame *p,
271  int *got_frame, AVPacket *avpkt)
272 {
273  uint8_t ctable[128];
274  QpegContext * const a = avctx->priv_data;
275  AVFrame * const ref = a->ref;
276  uint8_t* outdata;
277  int delta, intra, ret;
278 
279  if (avpkt->size < 0x86) {
280  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
281  return AVERROR_INVALIDDATA;
282  }
283 
284  bytestream2_init(&a->buffer, avpkt->data, avpkt->size);
285 
286  if ((ret = ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF)) < 0)
287  return ret;
288  outdata = p->data[0];
289  bytestream2_skip(&a->buffer, 4);
290  bytestream2_get_buffer(&a->buffer, ctable, 128);
291  bytestream2_skip(&a->buffer, 1);
292 
293  delta = bytestream2_get_byte(&a->buffer);
294  intra = delta == 0x10;
295  if (intra) {
296  qpeg_decode_intra(a, outdata, p->linesize[0], avctx->width, avctx->height);
297  } else {
298  qpeg_decode_inter(a, outdata, p->linesize[0], avctx->width, avctx->height, delta, ctable, ref->data[0]);
299  }
300 
301  /* make the palette available on the way out */
302  ff_copy_palette(a->pal, avpkt, avctx);
303  memcpy(p->data[1], a->pal, AVPALETTE_SIZE);
304 
305  if ((ret = av_frame_replace(ref, p)) < 0)
306  return ret;
307 
308  if (intra)
309  p->flags |= AV_FRAME_FLAG_KEY;
310  else
311  p->flags &= ~AV_FRAME_FLAG_KEY;
312  p->pict_type = intra ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
313 
314  *got_frame = 1;
315 
316  return avpkt->size;
317 }
318 
320 {
321  QpegContext * const a = avctx->priv_data;
322  int i, pal_size;
323  const uint8_t *pal_src;
324 
325  av_frame_unref(a->ref);
326 
327  pal_size = FFMIN(1024U, avctx->extradata_size);
328  pal_src = avctx->extradata + avctx->extradata_size - pal_size;
329 
330  for (i=0; i<pal_size/4; i++)
331  a->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i);
332 }
333 
335 {
336  QpegContext * const a = avctx->priv_data;
337 
338  av_frame_free(&a->ref);
339 
340  return 0;
341 }
342 
343 static av_cold int decode_init(AVCodecContext *avctx){
344  QpegContext * const a = avctx->priv_data;
345 
346  a->avctx = avctx;
347  avctx->pix_fmt= AV_PIX_FMT_PAL8;
348 
349  a->ref = av_frame_alloc();
350  if (!a->ref)
351  return AVERROR(ENOMEM);
352 
353  decode_flush(avctx);
354 
355  return 0;
356 }
357 
359  .p.name = "qpeg",
360  CODEC_LONG_NAME("Q-team QPEG"),
361  .p.type = AVMEDIA_TYPE_VIDEO,
362  .p.id = AV_CODEC_ID_QPEG,
363  .priv_data_size = sizeof(QpegContext),
364  .init = decode_init,
365  .close = decode_end,
367  .flush = decode_flush,
368  .p.capabilities = AV_CODEC_CAP_DR1,
369  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
370 };
FF_CODEC_CAP_INIT_CLEANUP
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: codec_internal.h:42
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
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(const GetByteContext *g)
Definition: bytestream.h:158
qpeg_decode_inter
static void av_noinline qpeg_decode_inter(QpegContext *qctx, uint8_t *dst, int stride, int width, int height, int delta, const uint8_t *ctable, uint8_t *refdata)
Definition: qpeg.c:130
GetByteContext
Definition: bytestream.h:33
qpeg_decode_intra
static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst, int stride, int width, int height)
Definition: qpeg.c:41
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:64
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:427
step
trying all byte sequences megabyte in length and selecting the best looking sequence will yield cases to try But a word about which is also called distortion Distortion can be quantified by almost any quality measurement one chooses the sum of squared differences is used but more complex methods that consider psychovisual effects can be used as well It makes no difference in this discussion First step
Definition: rate_distortion.txt:58
AVPacket::data
uint8_t * data
Definition: packet.h:558
FFCodec
Definition: codec_internal.h:127
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, AVPacket *avpkt)
Definition: qpeg.c:270
c1
static const uint64_t c1
Definition: murmur3.c:52
close
static av_cold void close(AVCodecParserContext *s)
Definition: apv_parser.c:135
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
val
static double val(void *priv, double ch)
Definition: aeval.c:77
av_noinline
#define av_noinline
Definition: attributes.h:72
qpeg_table_h
static const uint8_t qpeg_table_h[16]
Definition: qpeg.c:124
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:52
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:210
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:642
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:515
QpegContext::buffer
GetByteContext buffer
Definition: qpeg.c:38
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:346
QpegContext::pal
uint32_t pal[256]
Definition: qpeg.c:37
AV_GET_BUFFER_FLAG_REF
#define AV_GET_BUFFER_FLAG_REF
The decoder will keep a reference to the frame and may reuse it later.
Definition: avcodec.h:411
decode.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:331
run
uint8_t run
Definition: svq3.c:207
AVPALETTE_SIZE
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:278
bytestream2_get_buffer
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:267
qpeg_table_w
static const uint8_t qpeg_table_w[16]
Definition: qpeg.c:126
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1720
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:368
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:559
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static void copy(const float *p1, float *p2, const int length)
Definition: vf_vaguedenoiser.c:186
height
#define height
Definition: dsp.h:89
codec_internal.h
dst
uint8_t ptrdiff_t const uint8_t ptrdiff_t int intptr_t intptr_t int int16_t * dst
Definition: dsp.h:87
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: qpeg.c:334
QpegContext::avctx
AVCodecContext * avctx
Definition: qpeg.c:35
a
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:41
AV_CODEC_ID_QPEG
@ AV_CODEC_ID_QPEG
Definition: codec_id.h:112
attributes.h
ff_qpeg_decoder
const FFCodec ff_qpeg_decoder
Definition: qpeg.c:358
QpegContext
Definition: qpeg.c:34
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
Out-of-band global headers that may be used by some codecs.
Definition: avcodec.h:514
delta
float delta
Definition: vorbis_enc_data.h:430
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:496
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:179
AVCodecContext::height
int height
Definition: avcodec.h:592
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:631
avcodec.h
stride
#define stride
Definition: h264pred_template.c:536
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:84
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: qpeg.c:343
ret
ret
Definition: filter_design.txt:187
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
U
#define U(x)
Definition: vpx_arith.h:37
av_frame_replace
int av_frame_replace(AVFrame *dst, const AVFrame *src)
Ensure the destination frame refers to the same data described by the source frame,...
Definition: frame.c:376
AVCodecContext
main external API structure.
Definition: avcodec.h:431
ref
static int ref[MAX_W *MAX_W]
Definition: jpeg2000dwt.c:117
Windows::Graphics::DirectX::Direct3D11::p
IDirect3DDxgiInterfaceAccess _COM_Outptr_ void ** p
Definition: vsrc_gfxcapture_winrt.hpp:53
QpegContext::ref
AVFrame * ref
Definition: qpeg.c:36
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:279
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:200
bytestream2_get_bufferu
static av_always_inline unsigned int bytestream2_get_bufferu(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:277
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:458
AVPacket
This structure stores compressed data.
Definition: packet.h:535
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:592
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
ff_copy_palette
int ff_copy_palette(void *dst, const AVPacket *src, void *logctx)
Check whether the side-data of src contains a palette of size AVPALETTE_SIZE; if so,...
Definition: decode.c:2251
width
#define width
Definition: dsp.h:89
decode_flush
static av_cold void decode_flush(AVCodecContext *avctx)
Definition: qpeg.c:319
skip
static void BS_FUNC() skip(BSCTX *bc, unsigned int n)
Skip n bits in the buffer.
Definition: bitstream_template.h:383