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utvideoenc.c
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1 /*
2  * Ut Video encoder
3  * Copyright (c) 2012 Jan Ekström
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  * Ut Video encoder
25  */
26 
27 #include "libavutil/imgutils.h"
28 #include "libavutil/intreadwrite.h"
29 #include "avcodec.h"
30 #include "internal.h"
31 #include "bswapdsp.h"
32 #include "bytestream.h"
33 #include "put_bits.h"
34 #include "huffyuvencdsp.h"
35 #include "mathops.h"
36 #include "utvideo.h"
37 #include "huffman.h"
38 
39 /* Compare huffentry symbols */
40 static int huff_cmp_sym(const void *a, const void *b)
41 {
42  const HuffEntry *aa = a, *bb = b;
43  return aa->sym - bb->sym;
44 }
45 
47 {
48  UtvideoContext *c = avctx->priv_data;
49  int i;
50 
51  av_freep(&avctx->coded_frame);
52  av_freep(&c->slice_bits);
53  for (i = 0; i < 4; i++)
54  av_freep(&c->slice_buffer[i]);
55 
56  return 0;
57 }
58 
60 {
61  UtvideoContext *c = avctx->priv_data;
62  int i, subsampled_height;
63  uint32_t original_format;
64 
65  c->avctx = avctx;
66  c->frame_info_size = 4;
67  c->slice_stride = FFALIGN(avctx->width, 32);
68 
69  switch (avctx->pix_fmt) {
70  case AV_PIX_FMT_RGB24:
71  c->planes = 3;
72  avctx->codec_tag = MKTAG('U', 'L', 'R', 'G');
73  original_format = UTVIDEO_RGB;
74  break;
75  case AV_PIX_FMT_RGBA:
76  c->planes = 4;
77  avctx->codec_tag = MKTAG('U', 'L', 'R', 'A');
78  original_format = UTVIDEO_RGBA;
79  break;
80  case AV_PIX_FMT_YUV420P:
81  if (avctx->width & 1 || avctx->height & 1) {
82  av_log(avctx, AV_LOG_ERROR,
83  "4:2:0 video requires even width and height.\n");
84  return AVERROR_INVALIDDATA;
85  }
86  c->planes = 3;
87  if (avctx->colorspace == AVCOL_SPC_BT709)
88  avctx->codec_tag = MKTAG('U', 'L', 'H', '0');
89  else
90  avctx->codec_tag = MKTAG('U', 'L', 'Y', '0');
91  original_format = UTVIDEO_420;
92  break;
93  case AV_PIX_FMT_YUV422P:
94  if (avctx->width & 1) {
95  av_log(avctx, AV_LOG_ERROR,
96  "4:2:2 video requires even width.\n");
97  return AVERROR_INVALIDDATA;
98  }
99  c->planes = 3;
100  if (avctx->colorspace == AVCOL_SPC_BT709)
101  avctx->codec_tag = MKTAG('U', 'L', 'H', '2');
102  else
103  avctx->codec_tag = MKTAG('U', 'L', 'Y', '2');
104  original_format = UTVIDEO_422;
105  break;
106  default:
107  av_log(avctx, AV_LOG_ERROR, "Unknown pixel format: %d\n",
108  avctx->pix_fmt);
109  return AVERROR_INVALIDDATA;
110  }
111 
112  ff_bswapdsp_init(&c->bdsp);
114 
115  /* Check the prediction method, and error out if unsupported */
116  if (avctx->prediction_method < 0 || avctx->prediction_method > 4) {
117  av_log(avctx, AV_LOG_WARNING,
118  "Prediction method %d is not supported in Ut Video.\n",
119  avctx->prediction_method);
121  }
122 
123  if (avctx->prediction_method == FF_PRED_PLANE) {
124  av_log(avctx, AV_LOG_ERROR,
125  "Plane prediction is not supported in Ut Video.\n");
127  }
128 
129  /* Convert from libavcodec prediction type to Ut Video's */
131 
132  if (c->frame_pred == PRED_GRADIENT) {
133  av_log(avctx, AV_LOG_ERROR, "Gradient prediction is not supported.\n");
135  }
136 
137  /*
138  * Check the asked slice count for obviously invalid
139  * values (> 256 or negative).
140  */
141  if (avctx->slices > 256 || avctx->slices < 0) {
142  av_log(avctx, AV_LOG_ERROR,
143  "Slice count %d is not supported in Ut Video (theoretical range is 0-256).\n",
144  avctx->slices);
145  return AVERROR(EINVAL);
146  }
147 
148  /* Check that the slice count is not larger than the subsampled height */
149  subsampled_height = avctx->height >> av_pix_fmt_desc_get(avctx->pix_fmt)->log2_chroma_h;
150  if (avctx->slices > subsampled_height) {
151  av_log(avctx, AV_LOG_ERROR,
152  "Slice count %d is larger than the subsampling-applied height %d.\n",
153  avctx->slices, subsampled_height);
154  return AVERROR(EINVAL);
155  }
156 
157  avctx->coded_frame = av_frame_alloc();
158 
159  if (!avctx->coded_frame) {
160  av_log(avctx, AV_LOG_ERROR, "Could not allocate frame.\n");
161  utvideo_encode_close(avctx);
162  return AVERROR(ENOMEM);
163  }
164 
165  /* extradata size is 4 * 32bit */
166  avctx->extradata_size = 16;
167 
168  avctx->extradata = av_mallocz(avctx->extradata_size +
170 
171  if (!avctx->extradata) {
172  av_log(avctx, AV_LOG_ERROR, "Could not allocate extradata.\n");
173  utvideo_encode_close(avctx);
174  return AVERROR(ENOMEM);
175  }
176 
177  for (i = 0; i < c->planes; i++) {
178  c->slice_buffer[i] = av_malloc(c->slice_stride * (avctx->height + 2) +
180  if (!c->slice_buffer[i]) {
181  av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer 1.\n");
182  utvideo_encode_close(avctx);
183  return AVERROR(ENOMEM);
184  }
185  }
186 
187  /*
188  * Set the version of the encoder.
189  * Last byte is "implementation ID", which is
190  * obtained from the creator of the format.
191  * Libavcodec has been assigned with the ID 0xF0.
192  */
193  AV_WB32(avctx->extradata, MKTAG(1, 0, 0, 0xF0));
194 
195  /*
196  * Set the "original format"
197  * Not used for anything during decoding.
198  */
199  AV_WL32(avctx->extradata + 4, original_format);
200 
201  /* Write 4 as the 'frame info size' */
202  AV_WL32(avctx->extradata + 8, c->frame_info_size);
203 
204  /*
205  * Set how many slices are going to be used.
206  * By default uses multiple slices depending on the subsampled height.
207  * This enables multithreading in the official decoder.
208  */
209  if (!avctx->slices) {
210  c->slices = subsampled_height / 120;
211 
212  if (!c->slices)
213  c->slices = 1;
214  else if (c->slices > 256)
215  c->slices = 256;
216  } else {
217  c->slices = avctx->slices;
218  }
219 
220  /* Set compression mode */
221  c->compression = COMP_HUFF;
222 
223  /*
224  * Set the encoding flags:
225  * - Slice count minus 1
226  * - Interlaced encoding mode flag, set to zero for now.
227  * - Compression mode (none/huff)
228  * And write the flags.
229  */
230  c->flags = (c->slices - 1) << 24;
231  c->flags |= 0 << 11; // bit field to signal interlaced encoding mode
232  c->flags |= c->compression;
233 
234  AV_WL32(avctx->extradata + 12, c->flags);
235 
236  return 0;
237 }
238 
239 static void mangle_rgb_planes(uint8_t *dst[4], int dst_stride, uint8_t *src,
240  int step, int stride, int width, int height)
241 {
242  int i, j;
243  int k = 2 * dst_stride;
244  unsigned int g;
245 
246  for (j = 0; j < height; j++) {
247  if (step == 3) {
248  for (i = 0; i < width * step; i += step) {
249  g = src[i + 1];
250  dst[0][k] = g;
251  g += 0x80;
252  dst[1][k] = src[i + 2] - g;
253  dst[2][k] = src[i + 0] - g;
254  k++;
255  }
256  } else {
257  for (i = 0; i < width * step; i += step) {
258  g = src[i + 1];
259  dst[0][k] = g;
260  g += 0x80;
261  dst[1][k] = src[i + 2] - g;
262  dst[2][k] = src[i + 0] - g;
263  dst[3][k] = src[i + 3];
264  k++;
265  }
266  }
267  k += dst_stride - width;
268  src += stride;
269  }
270 }
271 
272 /* Write data to a plane with left prediction */
273 static void left_predict(uint8_t *src, uint8_t *dst, int stride,
274  int width, int height)
275 {
276  int i, j;
277  uint8_t prev;
278 
279  prev = 0x80; /* Set the initial value */
280  for (j = 0; j < height; j++) {
281  for (i = 0; i < width; i++) {
282  *dst++ = src[i] - prev;
283  prev = src[i];
284  }
285  src += stride;
286  }
287 }
288 
289 /* Write data to a plane with median prediction */
291  int width, int height)
292 {
293  int i, j;
294  int A, B;
295  uint8_t prev;
296 
297  /* First line uses left neighbour prediction */
298  prev = 0x80; /* Set the initial value */
299  for (i = 0; i < width; i++) {
300  *dst++ = src[i] - prev;
301  prev = src[i];
302  }
303 
304  if (height == 1)
305  return;
306 
307  src += stride;
308 
309  /*
310  * Second line uses top prediction for the first sample,
311  * and median for the rest.
312  */
313  A = B = 0;
314 
315  /* Rest of the coded part uses median prediction */
316  for (j = 1; j < height; j++) {
317  c->hdsp.sub_hfyu_median_pred(dst, src - stride, src, width, &A, &B);
318  dst += width;
319  src += stride;
320  }
321 }
322 
323 /* Count the usage of values in a plane */
324 static void count_usage(uint8_t *src, int width,
325  int height, uint64_t *counts)
326 {
327  int i, j;
328 
329  for (j = 0; j < height; j++) {
330  for (i = 0; i < width; i++) {
331  counts[src[i]]++;
332  }
333  src += width;
334  }
335 }
336 
337 /* Calculate the actual huffman codes from the code lengths */
338 static void calculate_codes(HuffEntry *he)
339 {
340  int last, i;
341  uint32_t code;
342 
343  qsort(he, 256, sizeof(*he), ff_ut_huff_cmp_len);
344 
345  last = 255;
346  while (he[last].len == 255 && last)
347  last--;
348 
349  code = 1;
350  for (i = last; i >= 0; i--) {
351  he[i].code = code >> (32 - he[i].len);
352  code += 0x80000000u >> (he[i].len - 1);
353  }
354 
355  qsort(he, 256, sizeof(*he), huff_cmp_sym);
356 }
357 
358 /* Write huffman bit codes to a memory block */
359 static int write_huff_codes(uint8_t *src, uint8_t *dst, int dst_size,
360  int width, int height, HuffEntry *he)
361 {
362  PutBitContext pb;
363  int i, j;
364  int count;
365 
366  init_put_bits(&pb, dst, dst_size);
367 
368  /* Write the codes */
369  for (j = 0; j < height; j++) {
370  for (i = 0; i < width; i++)
371  put_bits(&pb, he[src[i]].len, he[src[i]].code);
372 
373  src += width;
374  }
375 
376  /* Pad output to a 32bit boundary */
377  count = put_bits_count(&pb) & 0x1F;
378 
379  if (count)
380  put_bits(&pb, 32 - count, 0);
381 
382  /* Get the amount of bits written */
383  count = put_bits_count(&pb);
384 
385  /* Flush the rest with zeroes */
386  flush_put_bits(&pb);
387 
388  return count;
389 }
390 
392  uint8_t *dst, int stride, int plane_no,
393  int width, int height, PutByteContext *pb)
394 {
395  UtvideoContext *c = avctx->priv_data;
396  uint8_t lengths[256];
397  uint64_t counts[256] = { 0 };
398 
399  HuffEntry he[256];
400 
401  uint32_t offset = 0, slice_len = 0;
402  const int cmask = ~(!plane_no && avctx->pix_fmt == AV_PIX_FMT_YUV420P);
403  int i, sstart, send = 0;
404  int symbol;
405  int ret;
406 
407  /* Do prediction / make planes */
408  switch (c->frame_pred) {
409  case PRED_NONE:
410  for (i = 0; i < c->slices; i++) {
411  sstart = send;
412  send = height * (i + 1) / c->slices & cmask;
413  av_image_copy_plane(dst + sstart * width, width,
414  src + sstart * stride, stride,
415  width, send - sstart);
416  }
417  break;
418  case PRED_LEFT:
419  for (i = 0; i < c->slices; i++) {
420  sstart = send;
421  send = height * (i + 1) / c->slices & cmask;
422  left_predict(src + sstart * stride, dst + sstart * width,
423  stride, width, send - sstart);
424  }
425  break;
426  case PRED_MEDIAN:
427  for (i = 0; i < c->slices; i++) {
428  sstart = send;
429  send = height * (i + 1) / c->slices & cmask;
430  median_predict(c, src + sstart * stride, dst + sstart * width,
431  stride, width, send - sstart);
432  }
433  break;
434  default:
435  av_log(avctx, AV_LOG_ERROR, "Unknown prediction mode: %d\n",
436  c->frame_pred);
438  }
439 
440  /* Count the usage of values */
441  count_usage(dst, width, height, counts);
442 
443  /* Check for a special case where only one symbol was used */
444  for (symbol = 0; symbol < 256; symbol++) {
445  /* If non-zero count is found, see if it matches width * height */
446  if (counts[symbol]) {
447  /* Special case if only one symbol was used */
448  if (counts[symbol] == width * (int64_t)height) {
449  /*
450  * Write a zero for the single symbol
451  * used in the plane, else 0xFF.
452  */
453  for (i = 0; i < 256; i++) {
454  if (i == symbol)
455  bytestream2_put_byte(pb, 0);
456  else
457  bytestream2_put_byte(pb, 0xFF);
458  }
459 
460  /* Write zeroes for lengths */
461  for (i = 0; i < c->slices; i++)
462  bytestream2_put_le32(pb, 0);
463 
464  /* And that's all for that plane folks */
465  return 0;
466  }
467  break;
468  }
469  }
470 
471  /* Calculate huffman lengths */
472  if ((ret = ff_huff_gen_len_table(lengths, counts, 256, 1)) < 0)
473  return ret;
474 
475  /*
476  * Write the plane's header into the output packet:
477  * - huffman code lengths (256 bytes)
478  * - slice end offsets (gotten from the slice lengths)
479  */
480  for (i = 0; i < 256; i++) {
481  bytestream2_put_byte(pb, lengths[i]);
482 
483  he[i].len = lengths[i];
484  he[i].sym = i;
485  }
486 
487  /* Calculate the huffman codes themselves */
488  calculate_codes(he);
489 
490  send = 0;
491  for (i = 0; i < c->slices; i++) {
492  sstart = send;
493  send = height * (i + 1) / c->slices & cmask;
494 
495  /*
496  * Write the huffman codes to a buffer,
497  * get the offset in bits and convert to bytes.
498  */
499  offset += write_huff_codes(dst + sstart * width, c->slice_bits,
500  width * height + 4, width,
501  send - sstart, he) >> 3;
502 
503  slice_len = offset - slice_len;
504 
505  /* Byteswap the written huffman codes */
506  c->bdsp.bswap_buf((uint32_t *) c->slice_bits,
507  (uint32_t *) c->slice_bits,
508  slice_len >> 2);
509 
510  /* Write the offset to the stream */
511  bytestream2_put_le32(pb, offset);
512 
513  /* Seek to the data part of the packet */
514  bytestream2_seek_p(pb, 4 * (c->slices - i - 1) +
515  offset - slice_len, SEEK_CUR);
516 
517  /* Write the slices' data into the output packet */
518  bytestream2_put_buffer(pb, c->slice_bits, slice_len);
519 
520  /* Seek back to the slice offsets */
521  bytestream2_seek_p(pb, -4 * (c->slices - i - 1) - offset,
522  SEEK_CUR);
523 
524  slice_len = offset;
525  }
526 
527  /* And at the end seek to the end of written slice(s) */
528  bytestream2_seek_p(pb, offset, SEEK_CUR);
529 
530  return 0;
531 }
532 
534  const AVFrame *pic, int *got_packet)
535 {
536  UtvideoContext *c = avctx->priv_data;
537  PutByteContext pb;
538 
539  uint32_t frame_info;
540 
541  uint8_t *dst;
542 
543  int width = avctx->width, height = avctx->height;
544  int i, ret = 0;
545 
546  /* Allocate a new packet if needed, and set it to the pointer dst */
547  ret = ff_alloc_packet2(avctx, pkt, (256 + 4 * c->slices + width * height) *
548  c->planes + 4);
549 
550  if (ret < 0)
551  return ret;
552 
553  dst = pkt->data;
554 
555  bytestream2_init_writer(&pb, dst, pkt->size);
556 
557  av_fast_padded_malloc(&c->slice_bits, &c->slice_bits_size, width * height + 4);
558 
559  if (!c->slice_bits) {
560  av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer 2.\n");
561  return AVERROR(ENOMEM);
562  }
563 
564  /* In case of RGB, mangle the planes to Ut Video's format */
565  if (avctx->pix_fmt == AV_PIX_FMT_RGBA || avctx->pix_fmt == AV_PIX_FMT_RGB24)
567  c->planes, pic->linesize[0], width, height);
568 
569  /* Deal with the planes */
570  switch (avctx->pix_fmt) {
571  case AV_PIX_FMT_RGB24:
572  case AV_PIX_FMT_RGBA:
573  for (i = 0; i < c->planes; i++) {
574  ret = encode_plane(avctx, c->slice_buffer[i] + 2 * c->slice_stride,
575  c->slice_buffer[i], c->slice_stride, i,
576  width, height, &pb);
577 
578  if (ret) {
579  av_log(avctx, AV_LOG_ERROR, "Error encoding plane %d.\n", i);
580  return ret;
581  }
582  }
583  break;
584  case AV_PIX_FMT_YUV422P:
585  for (i = 0; i < c->planes; i++) {
586  ret = encode_plane(avctx, pic->data[i], c->slice_buffer[0],
587  pic->linesize[i], i, width >> !!i, height, &pb);
588 
589  if (ret) {
590  av_log(avctx, AV_LOG_ERROR, "Error encoding plane %d.\n", i);
591  return ret;
592  }
593  }
594  break;
595  case AV_PIX_FMT_YUV420P:
596  for (i = 0; i < c->planes; i++) {
597  ret = encode_plane(avctx, pic->data[i], c->slice_buffer[0],
598  pic->linesize[i], i, width >> !!i, height >> !!i,
599  &pb);
600 
601  if (ret) {
602  av_log(avctx, AV_LOG_ERROR, "Error encoding plane %d.\n", i);
603  return ret;
604  }
605  }
606  break;
607  default:
608  av_log(avctx, AV_LOG_ERROR, "Unknown pixel format: %d\n",
609  avctx->pix_fmt);
610  return AVERROR_INVALIDDATA;
611  }
612 
613  /*
614  * Write frame information (LE 32bit unsigned)
615  * into the output packet.
616  * Contains the prediction method.
617  */
618  frame_info = c->frame_pred << 8;
619  bytestream2_put_le32(&pb, frame_info);
620 
621  /*
622  * At least currently Ut Video is IDR only.
623  * Set flags accordingly.
624  */
625  avctx->coded_frame->key_frame = 1;
627 
628  pkt->size = bytestream2_tell_p(&pb);
629  pkt->flags |= AV_PKT_FLAG_KEY;
630 
631  /* Packet should be done */
632  *got_packet = 1;
633 
634  return 0;
635 }
636 
638  .name = "utvideo",
639  .long_name = NULL_IF_CONFIG_SMALL("Ut Video"),
640  .type = AVMEDIA_TYPE_VIDEO,
641  .id = AV_CODEC_ID_UTVIDEO,
642  .priv_data_size = sizeof(UtvideoContext),
644  .encode2 = utvideo_encode_frame,
647  .pix_fmts = (const enum AVPixelFormat[]) {
650  },
651 };