FFmpeg
qtrleenc.c
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1 /*
2  * Quicktime Animation (RLE) Video Encoder
3  * Copyright (C) 2007 Clemens Fruhwirth
4  * Copyright (C) 2007 Alexis Ballier
5  *
6  * This file is based on flashsvenc.c.
7  *
8  * This file is part of FFmpeg.
9  *
10  * FFmpeg is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * FFmpeg is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with FFmpeg; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
25 #include "libavutil/imgutils.h"
26 #include "avcodec.h"
27 #include "bytestream.h"
28 #include "encode.h"
29 #include "internal.h"
30 
31 /** Maximum RLE code for bulk copy */
32 #define MAX_RLE_BULK 127
33 /** Maximum RLE code for repeat */
34 #define MAX_RLE_REPEAT 128
35 /** Maximum RLE code for skip */
36 #define MAX_RLE_SKIP 254
37 
38 typedef struct QtrleEncContext {
42  unsigned int max_buf_size;
44  /**
45  * This array will contain at ith position the value of the best RLE code
46  * if the line started at pixel i
47  * There can be 3 values :
48  * skip (0) : skip as much as possible pixels because they are equal to the
49  * previous frame ones
50  * repeat (<-1) : repeat that pixel -rle_code times, still as much as
51  * possible
52  * copy (>0) : copy the raw next rle_code pixels */
53  signed char *rlecode_table;
54  /**
55  * This array will contain the length of the best rle encoding of the line
56  * starting at ith pixel */
58  /**
59  * Will contain at ith position the number of consecutive pixels equal to the previous
60  * frame starting from pixel i */
61  uint8_t* skip_table;
62 
63  /** Encoded frame is a key frame */
64  int key_frame;
66 
68 {
69  QtrleEncContext *s = avctx->priv_data;
70 
71  av_frame_free(&s->previous_frame);
72  av_free(s->rlecode_table);
73  av_free(s->length_table);
74  av_free(s->skip_table);
75  return 0;
76 }
77 
79 {
80  QtrleEncContext *s = avctx->priv_data;
81 
82  if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
83  return AVERROR(EINVAL);
84  }
85  s->avctx=avctx;
86  s->logical_width=avctx->width;
87 
88  switch (avctx->pix_fmt) {
89  case AV_PIX_FMT_GRAY8:
90  if (avctx->width % 4) {
91  av_log(avctx, AV_LOG_ERROR, "Width not being a multiple of 4 is not supported\n");
92  return AVERROR(EINVAL);
93  }
94  s->logical_width = avctx->width / 4;
95  s->pixel_size = 4;
96  break;
98  s->pixel_size = 2;
99  break;
100  case AV_PIX_FMT_RGB24:
101  s->pixel_size = 3;
102  break;
103  case AV_PIX_FMT_ARGB:
104  s->pixel_size = 4;
105  break;
106  default:
107  av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
108  break;
109  }
110  avctx->bits_per_coded_sample = avctx->pix_fmt == AV_PIX_FMT_GRAY8 ? 40 : s->pixel_size*8;
111 
112  s->rlecode_table = av_mallocz(s->logical_width);
113  s->skip_table = av_mallocz(s->logical_width);
114  s->length_table = av_calloc(s->logical_width + 1, sizeof(*s->length_table));
115  if (!s->skip_table || !s->length_table || !s->rlecode_table) {
116  av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
117  return AVERROR(ENOMEM);
118  }
119  s->previous_frame = av_frame_alloc();
120  if (!s->previous_frame) {
121  av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
122  return AVERROR(ENOMEM);
123  }
124 
125  s->max_buf_size = s->logical_width*s->avctx->height*s->pixel_size*2 /* image base material */
126  + 15 /* header + footer */
127  + s->avctx->height*2 /* skip code+rle end */
128  + s->logical_width/MAX_RLE_BULK + 1 /* rle codes */;
129 
130  return 0;
131 }
132 
133 /**
134  * Compute the best RLE sequence for a line
135  */
136 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
137 {
138  int width=s->logical_width;
139  int i;
140  signed char rlecode;
141 
142  /* This will be the number of pixels equal to the previous frame one's
143  * starting from the ith pixel */
144  unsigned int skipcount;
145  /* This will be the number of consecutive equal pixels in the current
146  * frame, starting from the ith one also */
147  unsigned int av_uninit(repeatcount);
148 
149  /* The cost of the three different possibilities */
150  int total_skip_cost;
151  int total_repeat_cost;
152 
153  int base_bulk_cost;
154  int lowest_bulk_cost;
155  int lowest_bulk_cost_index;
156  int sec_lowest_bulk_cost;
157  int sec_lowest_bulk_cost_index;
158 
159  const uint8_t *this_line = p->data[0] + line * p->linesize[0] + width * s->pixel_size;
160  /* There might be no earlier frame if the current frame is a keyframe.
161  * So just use a pointer to the current frame to avoid a check
162  * to avoid NULL - s->pixel_size (which is undefined behaviour). */
163  const uint8_t *prev_line = s->key_frame ? this_line
164  : s->previous_frame->data[0]
165  + line * s->previous_frame->linesize[0]
166  + width * s->pixel_size;
167 
168  s->length_table[width] = 0;
169  skipcount = 0;
170 
171  /* Initial values */
172  lowest_bulk_cost = INT_MAX / 2;
173  lowest_bulk_cost_index = width;
174  sec_lowest_bulk_cost = INT_MAX / 2;
175  sec_lowest_bulk_cost_index = width;
176 
177  base_bulk_cost = 1 + s->pixel_size;
178 
179  for (i = width - 1; i >= 0; i--) {
180 
181  int prev_bulk_cost;
182 
183  this_line -= s->pixel_size;
184  prev_line -= s->pixel_size;
185 
186  /* If our lowest bulk cost index is too far away, replace it
187  * with the next lowest bulk cost */
188  if (FFMIN(width, i + MAX_RLE_BULK) < lowest_bulk_cost_index) {
189  lowest_bulk_cost = sec_lowest_bulk_cost;
190  lowest_bulk_cost_index = sec_lowest_bulk_cost_index;
191 
192  sec_lowest_bulk_cost = INT_MAX / 2;
193  sec_lowest_bulk_cost_index = width;
194  }
195 
196  /* Deal with the first pixel's bulk cost */
197  if (!i) {
198  base_bulk_cost++;
199  lowest_bulk_cost++;
200  sec_lowest_bulk_cost++;
201  }
202 
203  /* Look at the bulk cost of the previous loop and see if it is
204  * a new lower bulk cost */
205  prev_bulk_cost = s->length_table[i + 1] + base_bulk_cost;
206  if (prev_bulk_cost <= sec_lowest_bulk_cost) {
207  /* If it's lower than the 2nd lowest, then it may be lower
208  * than the lowest */
209  if (prev_bulk_cost <= lowest_bulk_cost) {
210 
211  /* If we have found a new lowest bulk cost,
212  * then the 2nd lowest bulk cost is now farther than the
213  * lowest bulk cost, and will never be used */
214  sec_lowest_bulk_cost = INT_MAX / 2;
215 
216  lowest_bulk_cost = prev_bulk_cost;
217  lowest_bulk_cost_index = i + 1;
218  } else {
219  /* Then it must be the 2nd lowest bulk cost */
220  sec_lowest_bulk_cost = prev_bulk_cost;
221  sec_lowest_bulk_cost_index = i + 1;
222  }
223  }
224 
225  if (!s->key_frame && !memcmp(this_line, prev_line, s->pixel_size))
226  skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
227  else
228  skipcount = 0;
229 
230  total_skip_cost = s->length_table[i + skipcount] + 2;
231  s->skip_table[i] = skipcount;
232 
233 
234  if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
235  repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
236  else
237  repeatcount = 1;
238 
239  total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
240 
241  /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
242  * so let's make it aware */
243  if (i == 0) {
244  total_skip_cost--;
245  total_repeat_cost++;
246  }
247 
248  if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
249  /* repeat is the best */
250  s->length_table[i] = total_repeat_cost;
251  s->rlecode_table[i] = -repeatcount;
252  }
253  else if (skipcount > 0) {
254  /* skip is the best choice here */
255  s->length_table[i] = total_skip_cost;
256  s->rlecode_table[i] = 0;
257  }
258  else {
259  /* We cannot do neither skip nor repeat
260  * thus we use the best bulk copy */
261 
262  s->length_table[i] = lowest_bulk_cost;
263  s->rlecode_table[i] = lowest_bulk_cost_index - i;
264 
265  }
266 
267  /* These bulk costs increase every iteration */
268  lowest_bulk_cost += s->pixel_size;
269  sec_lowest_bulk_cost += s->pixel_size;
270  }
271 
272  /* Good! Now we have the best sequence for this line, let's output it. */
273 
274  /* We do a special case for the first pixel so that we avoid testing it in
275  * the whole loop */
276 
277  i=0;
278  this_line = p-> data[0] + line*p->linesize[0];
279 
280  if (s->rlecode_table[0] == 0) {
281  bytestream_put_byte(buf, s->skip_table[0] + 1);
282  i += s->skip_table[0];
283  }
284  else bytestream_put_byte(buf, 1);
285 
286 
287  while (i < width) {
288  rlecode = s->rlecode_table[i];
289  bytestream_put_byte(buf, rlecode);
290  if (rlecode == 0) {
291  /* Write a skip sequence */
292  bytestream_put_byte(buf, s->skip_table[i] + 1);
293  i += s->skip_table[i];
294  }
295  else if (rlecode > 0) {
296  /* bulk copy */
297  if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
298  int j;
299  // QT grayscale colorspace has 0=white and 255=black, we will
300  // ignore the palette that is included in the AVFrame because
301  // AV_PIX_FMT_GRAY8 has defined color mapping
302  for (j = 0; j < rlecode*s->pixel_size; ++j)
303  bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
304  } else {
305  bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
306  }
307  i += rlecode;
308  }
309  else {
310  /* repeat the bits */
311  if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
312  int j;
313  // QT grayscale colorspace has 0=white and 255=black, ...
314  for (j = 0; j < s->pixel_size; ++j)
315  bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
316  } else {
317  bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
318  }
319  i -= rlecode;
320  }
321  }
322  bytestream_put_byte(buf, -1); // end RLE line
323 }
324 
325 /** Encode frame including header */
326 static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
327 {
328  int i;
329  int start_line = 0;
330  int end_line = s->avctx->height;
331  uint8_t *orig_buf = buf;
332 
333  if (!s->key_frame) {
334  unsigned line_size = s->logical_width * s->pixel_size;
335  for (start_line = 0; start_line < s->avctx->height; start_line++)
336  if (memcmp(p->data[0] + start_line*p->linesize[0],
337  s->previous_frame->data[0] + start_line * s->previous_frame->linesize[0],
338  line_size))
339  break;
340 
341  for (end_line=s->avctx->height; end_line > start_line; end_line--)
342  if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
343  s->previous_frame->data[0] + (end_line - 1) * s->previous_frame->linesize[0],
344  line_size))
345  break;
346  }
347 
348  bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
349 
350  if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
351  bytestream_put_be16(&buf, 0); // header
352  else {
353  bytestream_put_be16(&buf, 8); // header
354  bytestream_put_be16(&buf, start_line); // starting line
355  bytestream_put_be16(&buf, 0); // unknown
356  bytestream_put_be16(&buf, end_line - start_line); // lines to update
357  bytestream_put_be16(&buf, 0); // unknown
358  }
359  for (i = start_line; i < end_line; i++)
360  qtrle_encode_line(s, p, i, &buf);
361 
362  bytestream_put_byte(&buf, 0); // zero skip code = frame finished
363  AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
364  return buf - orig_buf;
365 }
366 
368  const AVFrame *pict, int *got_packet)
369 {
370  QtrleEncContext * const s = avctx->priv_data;
371  int ret;
372 
373  if ((ret = ff_alloc_packet(avctx, pkt, s->max_buf_size)) < 0)
374  return ret;
375 
376  if (avctx->gop_size == 0 || !s->previous_frame->data[0] ||
377  (s->avctx->frame_number % avctx->gop_size) == 0) {
378  /* I-Frame */
379  s->key_frame = 1;
380  } else {
381  /* P-Frame */
382  s->key_frame = 0;
383  }
384 
385  pkt->size = encode_frame(s, pict, pkt->data);
386 
387  /* save the current frame */
388  av_frame_unref(s->previous_frame);
389  ret = av_frame_ref(s->previous_frame, pict);
390  if (ret < 0) {
391  av_log(avctx, AV_LOG_ERROR, "cannot add reference\n");
392  return ret;
393  }
394 
395  if (s->key_frame)
397  *got_packet = 1;
398 
399  return 0;
400 }
401 
403  .name = "qtrle",
404  .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
405  .type = AVMEDIA_TYPE_VIDEO,
406  .id = AV_CODEC_ID_QTRLE,
407  .priv_data_size = sizeof(QtrleEncContext),
409  .encode2 = qtrle_encode_frame,
410  .close = qtrle_encode_end,
411  .pix_fmts = (const enum AVPixelFormat[]){
413  },
415 };
AVCodec
AVCodec.
Definition: codec.h:202
FF_CODEC_CAP_INIT_THREADSAFE
#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:42
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
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
MAX_RLE_BULK
#define MAX_RLE_BULK
Maximum RLE code for bulk copy.
Definition: qtrleenc.c:32
QtrleEncContext::avctx
AVCodecContext * avctx
Definition: qtrleenc.c:39
QtrleEncContext::length_table
int * length_table
This array will contain the length of the best rle encoding of the line starting at ith pixel.
Definition: qtrleenc.c:57
QtrleEncContext::pixel_size
int pixel_size
Definition: qtrleenc.c:40
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:112
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
encode.h
data
const char data[16]
Definition: mxf.c:143
qtrle_encode_end
static av_cold int qtrle_encode_end(AVCodecContext *avctx)
Definition: qtrleenc.c:67
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:425
AV_PIX_FMT_RGB555BE
@ AV_PIX_FMT_RGB555BE
packed RGB 5:5:5, 16bpp, (msb)1X 5R 5G 5B(lsb), big-endian , X=unused/undefined
Definition: pixfmt.h:107
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:317
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:99
pkt
AVPacket * pkt
Definition: movenc.c:59
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
width
#define width
s
#define s(width, name)
Definition: cbs_vp9.c:257
qtrle_encode_line
static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
Compute the best RLE sequence for a line.
Definition: qtrleenc.c:136
pix_fmts
static enum AVPixelFormat pix_fmts[]
Definition: libkvazaar.c:290
QtrleEncContext::logical_width
int logical_width
Definition: qtrleenc.c:43
MAX_RLE_SKIP
#define MAX_RLE_SKIP
Maximum RLE code for skip.
Definition: qtrleenc.c:36
QtrleEncContext::key_frame
int key_frame
Encoded frame is a key frame.
Definition: qtrleenc.c:64
QtrleEncContext::skip_table
uint8_t * skip_table
Will contain at ith position the number of consecutive pixels equal to the previous frame starting fr...
Definition: qtrleenc.c:61
ff_qtrle_encoder
const AVCodec ff_qtrle_encoder
Definition: qtrleenc.c:402
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:74
AV_WB32
#define AV_WB32(p, v)
Definition: intreadwrite.h:419
MAX_RLE_REPEAT
#define MAX_RLE_REPEAT
Maximum RLE code for repeat.
Definition: qtrleenc.c:34
AV_PIX_FMT_RGB24
@ AV_PIX_FMT_RGB24
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:68
AVPacket::size
int size
Definition: packet.h:374
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
AVCodecContext::gop_size
int gop_size
the number of pictures in a group of pictures, or 0 for intra_only
Definition: avcodec.h:578
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:327
encode_frame
static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
Encode frame including header.
Definition: qtrleenc.c:326
QtrleEncContext::rlecode_table
signed char * rlecode_table
This array will contain at ith position the value of the best RLE code if the line started at pixel i...
Definition: qtrleenc.c:53
line
Definition: graph2dot.c:48
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:379
QtrleEncContext::max_buf_size
unsigned int max_buf_size
Definition: qtrleenc.c:42
AV_PIX_FMT_ARGB
@ AV_PIX_FMT_ARGB
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:92
AVCodecContext::bits_per_coded_sample
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1418
bytestream_put_buffer
static av_always_inline void bytestream_put_buffer(uint8_t **b, const uint8_t *src, unsigned int size)
Definition: bytestream.h:372
i
int i
Definition: input.c:406
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: internal.h:50
QtrleEncContext::previous_frame
AVFrame * previous_frame
Definition: qtrleenc.c:41
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:437
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:263
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:209
AVCodecContext::height
int height
Definition: avcodec.h:556
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:593
av_calloc
void * av_calloc(size_t nmemb, size_t size)
Definition: mem.c:271
avcodec.h
av_uninit
#define av_uninit(x)
Definition: attributes.h:154
ret
ret
Definition: filter_design.txt:187
AVCodecContext
main external API structure.
Definition: avcodec.h:383
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
qtrle_encode_frame
static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *pict, int *got_packet)
Definition: qtrleenc.c:367
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AV_CODEC_ID_QTRLE
@ AV_CODEC_ID_QTRLE
Definition: codec_id.h:105
qtrle_encode_init
static av_cold int qtrle_encode_init(AVCodecContext *avctx)
Definition: qtrleenc.c:78
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
AVPacket
This structure stores compressed data.
Definition: packet.h:350
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:410
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:556
bytestream.h
imgutils.h
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:334
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
av_image_check_size
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...
Definition: imgutils.c:318
QtrleEncContext
Definition: qtrleenc.c:38
ff_alloc_packet
int ff_alloc_packet(AVCodecContext *avctx, AVPacket *avpkt, int64_t size)
Check AVPacket size and allocate data.
Definition: encode.c:34