FFmpeg  4.4
flashsvenc.c
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1 /*
2  * Flash Screen Video encoder
3  * Copyright (C) 2004 Alex Beregszaszi
4  * Copyright (C) 2006 Benjamin Larsson
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /* Encoding development sponsored by http://fh-campuswien.ac.at */
24 
25 /**
26  * @file
27  * Flash Screen Video encoder
28  * @author Alex Beregszaszi
29  * @author Benjamin Larsson
30  *
31  * A description of the bitstream format for Flash Screen Video version 1/2
32  * is part of the SWF File Format Specification (version 10), which can be
33  * downloaded from http://www.adobe.com/devnet/swf.html.
34  */
35 
36 /*
37  * Encoding ideas: A basic encoder would just use a fixed block size.
38  * Block sizes can be multiples of 16, from 16 to 256. The blocks don't
39  * have to be quadratic. A brute force search with a set of different
40  * block sizes should give a better result than to just use a fixed size.
41  *
42  * TODO:
43  * Don't reencode the frame in brute force mode if the frame is a dupe.
44  * Speed up. Make the difference check faster.
45  */
46 
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <zlib.h>
50 
51 #include "avcodec.h"
52 #include "internal.h"
53 #include "put_bits.h"
54 #include "bytestream.h"
55 
56 
57 typedef struct FlashSVContext {
63  int block_size;
65  uint8_t tmpblock[3 * 256 * 256];
67 
68 static int copy_region_enc(uint8_t *sptr, uint8_t *dptr, int dx, int dy,
69  int h, int w, int stride, uint8_t *pfptr)
70 {
71  int i, j;
72  uint8_t *nsptr;
73  uint8_t *npfptr;
74  int diff = 0;
75 
76  for (i = dx + h; i > dx; i--) {
77  nsptr = sptr + i * stride + dy * 3;
78  npfptr = pfptr + i * stride + dy * 3;
79  for (j = 0; j < w * 3; j++) {
80  diff |= npfptr[j] ^ nsptr[j];
81  dptr[j] = nsptr[j];
82  }
83  dptr += w * 3;
84  }
85  if (diff)
86  return 1;
87  return 0;
88 }
89 
91 {
92  FlashSVContext *s = avctx->priv_data;
93 
94  av_freep(&s->encbuffer);
95  av_freep(&s->previous_frame);
96 
97  return 0;
98 }
99 
101 {
102  FlashSVContext *s = avctx->priv_data;
103 
104  s->avctx = avctx;
105 
106  if (avctx->width > 4095 || avctx->height > 4095) {
107  av_log(avctx, AV_LOG_ERROR,
108  "Input dimensions too large, input must be max 4095x4095 !\n");
109  return AVERROR_INVALIDDATA;
110  }
111 
112  s->last_key_frame = 0;
113 
114  s->image_width = avctx->width;
115  s->image_height = avctx->height;
116 
117  s->encbuffer = av_mallocz(s->image_width * s->image_height * 3);
118 
119  if (!s->encbuffer) {
120  av_log(avctx, AV_LOG_ERROR, "Memory allocation failed.\n");
121  return AVERROR(ENOMEM);
122  }
123 
124  return 0;
125 }
126 
127 
128 static int encode_bitstream(FlashSVContext *s, const AVFrame *p, uint8_t *buf,
129  int buf_size, int block_width, int block_height,
130  uint8_t *previous_frame, int *I_frame)
131 {
132 
133  PutBitContext pb;
134  int h_blocks, v_blocks, h_part, v_part, i, j;
135  int buf_pos, res;
136  int pred_blocks = 0;
137 
138  init_put_bits(&pb, buf, buf_size);
139 
140  put_bits(&pb, 4, block_width / 16 - 1);
141  put_bits(&pb, 12, s->image_width);
142  put_bits(&pb, 4, block_height / 16 - 1);
143  put_bits(&pb, 12, s->image_height);
144  flush_put_bits(&pb);
145  buf_pos = 4;
146 
147  h_blocks = s->image_width / block_width;
148  h_part = s->image_width % block_width;
149  v_blocks = s->image_height / block_height;
150  v_part = s->image_height % block_height;
151 
152  /* loop over all block columns */
153  for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
154 
155  int y_pos = j * block_height; // vertical position in frame
156  int cur_blk_height = (j < v_blocks) ? block_height : v_part;
157 
158  /* loop over all block rows */
159  for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {
160  int x_pos = i * block_width; // horizontal position in frame
161  int cur_blk_width = (i < h_blocks) ? block_width : h_part;
162  int ret = Z_OK;
163  uint8_t *ptr = buf + buf_pos;
164 
165  /* copy the block to the temp buffer before compression
166  * (if it differs from the previous frame's block) */
167  res = copy_region_enc(p->data[0], s->tmpblock,
168  s->image_height - (y_pos + cur_blk_height + 1),
169  x_pos, cur_blk_height, cur_blk_width,
170  p->linesize[0], previous_frame);
171 
172  if (res || *I_frame) {
173  unsigned long zsize = 3 * block_width * block_height;
174  ret = compress2(ptr + 2, &zsize, s->tmpblock,
175  3 * cur_blk_width * cur_blk_height, 9);
176 
177  if (ret != Z_OK)
178  av_log(s->avctx, AV_LOG_ERROR,
179  "error while compressing block %dx%d\n", i, j);
180 
181  bytestream_put_be16(&ptr, zsize);
182  buf_pos += zsize + 2;
183  ff_dlog(s->avctx, "buf_pos = %d\n", buf_pos);
184  } else {
185  pred_blocks++;
186  bytestream_put_be16(&ptr, 0);
187  buf_pos += 2;
188  }
189  }
190  }
191 
192  if (pred_blocks)
193  *I_frame = 0;
194  else
195  *I_frame = 1;
196 
197  return buf_pos;
198 }
199 
200 
202  const AVFrame *pict, int *got_packet)
203 {
204  FlashSVContext * const s = avctx->priv_data;
205  const AVFrame * const p = pict;
206  uint8_t *pfptr;
207  int res;
208  int I_frame = 0;
209  int opt_w = 4, opt_h = 4;
210 
211  /* First frame needs to be a keyframe */
212  if (avctx->frame_number == 0) {
213  s->previous_frame = av_mallocz(FFABS(p->linesize[0]) * s->image_height);
214  if (!s->previous_frame) {
215  av_log(avctx, AV_LOG_ERROR, "Memory allocation failed.\n");
216  return AVERROR(ENOMEM);
217  }
218  I_frame = 1;
219  }
220 
221  if (p->linesize[0] < 0)
222  pfptr = s->previous_frame - (s->image_height - 1) * p->linesize[0];
223  else
224  pfptr = s->previous_frame;
225 
226  /* Check the placement of keyframes */
227  if (avctx->gop_size > 0 &&
228  avctx->frame_number >= s->last_key_frame + avctx->gop_size) {
229  I_frame = 1;
230  }
231 
232  if ((res = ff_alloc_packet2(avctx, pkt, s->image_width * s->image_height * 3, 0)) < 0)
233  return res;
234 
235  pkt->size = encode_bitstream(s, p, pkt->data, pkt->size, opt_w * 16, opt_h * 16,
236  pfptr, &I_frame);
237 
238  //save the current frame
239  if (p->linesize[0] > 0)
240  memcpy(s->previous_frame, p->data[0], s->image_height * p->linesize[0]);
241  else
242  memcpy(s->previous_frame,
243  p->data[0] + p->linesize[0] * (s->image_height - 1),
244  s->image_height * FFABS(p->linesize[0]));
245 
246  //mark the frame type so the muxer can mux it correctly
247  if (I_frame) {
248 #if FF_API_CODED_FRAME
251  avctx->coded_frame->key_frame = 1;
253 #endif
254  s->last_key_frame = avctx->frame_number;
255  ff_dlog(avctx, "Inserting keyframe at frame %d\n", avctx->frame_number);
256  } else {
257 #if FF_API_CODED_FRAME
260  avctx->coded_frame->key_frame = 0;
262 #endif
263  }
264 
265  if (I_frame)
267  *got_packet = 1;
268 
269  return 0;
270 }
271 
273  .name = "flashsv",
274  .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video"),
275  .type = AVMEDIA_TYPE_VIDEO,
276  .id = AV_CODEC_ID_FLASHSV,
277  .priv_data_size = sizeof(FlashSVContext),
279  .encode2 = flashsv_encode_frame,
280  .close = flashsv_encode_end,
282 };
#define av_cold
Definition: attributes.h:88
uint8_t
Libavcodec external API header.
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
#define s(width, name)
Definition: cbs_vp9.c:257
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
int ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int64_t min_size)
Check AVPacket size and/or allocate data.
Definition: encode.c:33
static av_cold int flashsv_encode_end(AVCodecContext *avctx)
Definition: flashsvenc.c:90
static int encode_bitstream(FlashSVContext *s, const AVFrame *p, uint8_t *buf, int buf_size, int block_width, int block_height, uint8_t *previous_frame, int *I_frame)
Definition: flashsvenc.c:128
static av_cold int flashsv_encode_init(AVCodecContext *avctx)
Definition: flashsvenc.c:100
static int copy_region_enc(uint8_t *sptr, uint8_t *dptr, int dx, int dy, int h, int w, int stride, uint8_t *pfptr)
Definition: flashsvenc.c:68
AVCodec ff_flashsv_encoder
Definition: flashsvenc.c:272
static int flashsv_encode_frame(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *pict, int *got_packet)
Definition: flashsvenc.c:201
@ AV_CODEC_ID_FLASHSV
Definition: codec_id.h:135
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:410
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:237
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:275
int i
Definition: input.c:407
static void put_bits(Jpeg2000EncoderContext *s, int val, int n)
put n times val bit
Definition: j2kenc.c:218
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:83
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:84
static enum AVPixelFormat pix_fmts[]
Definition: libkvazaar.c:303
uint8_t w
Definition: llviddspenc.c:39
int stride
Definition: mace.c:144
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
@ AV_PIX_FMT_BGR24
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:69
bitstream writer API
static void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
Initialize the PutBitContext s.
Definition: put_bits.h:57
static void flush_put_bits(PutBitContext *s)
Pad the end of the output stream with zeros.
Definition: put_bits.h:110
main external API structure.
Definition: avcodec.h:536
int width
picture width / height.
Definition: avcodec.h:709
attribute_deprecated AVFrame * coded_frame
the picture in the bitstream
Definition: avcodec.h:1764
int gop_size
the number of pictures in a group of pictures, or 0 for intra_only
Definition: avcodec.h:731
int frame_number
Frame counter, set by libavcodec.
Definition: avcodec.h:1227
void * priv_data
Definition: avcodec.h:563
AVCodec.
Definition: codec.h:197
const char * name
Name of the codec implementation.
Definition: codec.h:204
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:332
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:396
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:349
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:401
This structure stores compressed data.
Definition: packet.h:346
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:375
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
uint8_t * encbuffer
Definition: flashsvenc.c:62
uint8_t * previous_frame
Definition: flashsvenc.c:59
int last_key_frame
Definition: flashsvenc.c:64
int block_height
Definition: flashsv.c:55
uint8_t * tmpblock
Definition: flashsv.c:56
int image_height
Definition: flashsv.c:54
int block_width
Definition: flashsv.c:55
int image_width
Definition: flashsv.c:54
AVCodecContext * avctx
Definition: flashsv.c:52
int block_size
Definition: flashsv.c:57
#define ff_dlog(a,...)
#define av_freep(p)
#define av_log(a,...)
AVPacket * pkt
Definition: movenc.c:59
if(ret< 0)
Definition: vf_mcdeint.c:282
static av_always_inline int diff(const uint32_t a, const uint32_t b)