FFmpeg
midivid.c
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1 /*
2  * MidiVid decoder
3  * Copyright (c) 2019 Paul B Mahol
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 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 
26 #include "libavutil/imgutils.h"
27 #include "libavutil/internal.h"
28 #include "libavutil/intreadwrite.h"
29 #include "libavutil/mem.h"
30 
31 #define BITSTREAM_READER_LE
32 #include "avcodec.h"
33 #include "get_bits.h"
34 #include "bytestream.h"
35 #include "internal.h"
36 
37 typedef struct MidiVidContext {
39 
41  unsigned int uncompressed_size;
43 
46 
48 {
49  GetByteContext *gb = &s->gb;
51  GetByteContext idx9;
52  uint16_t nb_vectors, intra_flag;
53  const uint8_t *vec;
54  const uint8_t *mask_start;
55  uint8_t *skip;
56  uint32_t mask_size;
57  int idx9bits = 0;
58  int idx9val = 0;
59  uint32_t nb_blocks;
60 
61  nb_vectors = bytestream2_get_le16(gb);
62  intra_flag = !!bytestream2_get_le16(gb);
63  if (intra_flag) {
64  nb_blocks = (avctx->width / 2) * (avctx->height / 2);
65  } else {
66  int ret, skip_linesize, padding;
67 
68  nb_blocks = bytestream2_get_le32(gb);
69  skip_linesize = avctx->width >> 1;
70  mask_start = gb->buffer_start + bytestream2_tell(gb);
71  mask_size = (FFALIGN(avctx->width, 32) >> 2) * (avctx->height >> 2) >> 3;
72  padding = (FFALIGN(avctx->width, 32) - avctx->width) >> 2;
73 
74  if (bytestream2_get_bytes_left(gb) < mask_size)
75  return AVERROR_INVALIDDATA;
76 
77  ret = init_get_bits8(&mask, mask_start, mask_size);
78  if (ret < 0)
79  return ret;
80  bytestream2_skip(gb, mask_size);
81  skip = s->skip;
82 
83  for (int y = 0; y < avctx->height >> 2; y++) {
84  for (int x = 0; x < avctx->width >> 2; x++) {
85  int flag = !get_bits1(&mask);
86 
87  skip[(y*2) *skip_linesize + x*2 ] = flag;
88  skip[(y*2) *skip_linesize + x*2+1] = flag;
89  skip[(y*2+1)*skip_linesize + x*2 ] = flag;
90  skip[(y*2+1)*skip_linesize + x*2+1] = flag;
91  }
92  skip_bits_long(&mask, padding);
93  }
94  }
95 
96  vec = gb->buffer_start + bytestream2_tell(gb);
97  if (bytestream2_get_bytes_left(gb) < nb_vectors * 12)
98  return AVERROR_INVALIDDATA;
99  bytestream2_skip(gb, nb_vectors * 12);
100  if (nb_vectors > 256) {
101  if (bytestream2_get_bytes_left(gb) < (nb_blocks + 7 * !intra_flag) / 8)
102  return AVERROR_INVALIDDATA;
103  bytestream2_init(&idx9, gb->buffer_start + bytestream2_tell(gb), (nb_blocks + 7 * !intra_flag) / 8);
104  bytestream2_skip(gb, (nb_blocks + 7 * !intra_flag) / 8);
105  }
106 
107  skip = s->skip;
108 
109  for (int y = avctx->height - 2; y >= 0; y -= 2) {
110  uint8_t *dsty = frame->data[0] + y * frame->linesize[0];
111  uint8_t *dstu = frame->data[1] + y * frame->linesize[1];
112  uint8_t *dstv = frame->data[2] + y * frame->linesize[2];
113 
114  for (int x = 0; x < avctx->width; x += 2) {
115  int idx;
116 
117  if (!intra_flag && *skip++)
118  continue;
119  if (bytestream2_get_bytes_left(gb) <= 0)
120  return AVERROR_INVALIDDATA;
121  if (nb_vectors <= 256) {
122  idx = bytestream2_get_byte(gb);
123  } else {
124  if (idx9bits == 0) {
125  idx9val = bytestream2_get_byte(&idx9);
126  idx9bits = 8;
127  }
128  idx9bits--;
129  idx = bytestream2_get_byte(gb) | (((idx9val >> (7 - idx9bits)) & 1) << 8);
130  }
131  if (idx >= nb_vectors)
132  return AVERROR_INVALIDDATA;
133 
134  dsty[x +frame->linesize[0]] = vec[idx * 12 + 0];
135  dsty[x+1+frame->linesize[0]] = vec[idx * 12 + 3];
136  dsty[x] = vec[idx * 12 + 6];
137  dsty[x+1] = vec[idx * 12 + 9];
138 
139  dstu[x +frame->linesize[1]] = vec[idx * 12 + 1];
140  dstu[x+1+frame->linesize[1]] = vec[idx * 12 + 4];
141  dstu[x] = vec[idx * 12 + 7];
142  dstu[x+1] = vec[idx * 12 +10];
143 
144  dstv[x +frame->linesize[2]] = vec[idx * 12 + 2];
145  dstv[x+1+frame->linesize[2]] = vec[idx * 12 + 5];
146  dstv[x] = vec[idx * 12 + 8];
147  dstv[x+1] = vec[idx * 12 +11];
148  }
149  }
150 
151  return intra_flag;
152 }
153 
154 static ptrdiff_t lzss_uncompress(MidiVidContext *s, GetByteContext *gb, uint8_t *dst, unsigned int size)
155 {
156  uint8_t *dst_start = dst;
157  uint8_t *dst_end = dst + size;
158 
159  for (;bytestream2_get_bytes_left(gb) >= 3;) {
160  int op = bytestream2_get_le16(gb);
161 
162  for (int i = 0; i < 16; i++) {
163  if (op & 1) {
164  int s0 = bytestream2_get_byte(gb);
165  int s1 = bytestream2_get_byte(gb);
166  int offset = ((s0 & 0xF0) << 4) | s1;
167  int length = (s0 & 0xF) + 3;
168 
169  if (dst + length > dst_end ||
170  dst - offset < dst_start)
171  return AVERROR_INVALIDDATA;
172  if (offset > 0) {
173  for (int j = 0; j < length; j++) {
174  dst[j] = dst[j - offset];
175  }
176  }
177  dst += length;
178  } else {
179  if (dst >= dst_end)
180  return AVERROR_INVALIDDATA;
181  *dst++ = bytestream2_get_byte(gb);
182  }
183  op >>= 1;
184  }
185  }
186 
187  return dst - dst_start;
188 }
189 
190 static int decode_frame(AVCodecContext *avctx, void *data,
191  int *got_frame, AVPacket *avpkt)
192 {
193  MidiVidContext *s = avctx->priv_data;
194  GetByteContext *gb = &s->gb;
195  AVFrame *frame = s->frame;
196  int ret, key, uncompressed;
197 
198  if (avpkt->size <= 13)
199  return AVERROR_INVALIDDATA;
200 
201  bytestream2_init(gb, avpkt->data, avpkt->size);
202  bytestream2_skip(gb, 8);
203  uncompressed = bytestream2_get_le32(gb);
204 
205  if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
206  return ret;
207 
208  if (uncompressed) {
209  ret = decode_mvdv(s, avctx, frame);
210  } else {
211  av_fast_padded_malloc(&s->uncompressed, &s->uncompressed_size, 16LL * (avpkt->size - 12));
212  if (!s->uncompressed)
213  return AVERROR(ENOMEM);
214 
215  ret = lzss_uncompress(s, gb, s->uncompressed, s->uncompressed_size);
216  if (ret < 0)
217  return ret;
218  bytestream2_init(gb, s->uncompressed, ret);
219  ret = decode_mvdv(s, avctx, frame);
220  }
221 
222  if (ret < 0)
223  return ret;
224  key = ret;
225 
226  if ((ret = av_frame_ref(data, s->frame)) < 0)
227  return ret;
228 
230  frame->key_frame = key;
231  *got_frame = 1;
232 
233  return avpkt->size;
234 }
235 
237 {
238  MidiVidContext *s = avctx->priv_data;
239  int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
240 
241  if (avctx->width & 3 || avctx->height & 3)
242  ret = AVERROR_INVALIDDATA;
243 
244  if (ret < 0) {
245  av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
246  avctx->width, avctx->height);
247  return ret;
248  }
249 
250  avctx->pix_fmt = AV_PIX_FMT_YUV444P;
251 
252  s->frame = av_frame_alloc();
253  if (!s->frame)
254  return AVERROR(ENOMEM);
255  s->skip = av_calloc(avctx->width >> 1, avctx->height >> 1);
256  if (!s->skip)
257  return AVERROR(ENOMEM);
258 
259  return 0;
260 }
261 
262 static void decode_flush(AVCodecContext *avctx)
263 {
264  MidiVidContext *s = avctx->priv_data;
265 
266  av_frame_unref(s->frame);
267 }
268 
270 {
271  MidiVidContext *s = avctx->priv_data;
272 
273  av_frame_free(&s->frame);
274  av_freep(&s->uncompressed);
275  av_freep(&s->skip);
276 
277  return 0;
278 }
279 
281  .name = "mvdv",
282  .long_name = NULL_IF_CONFIG_SMALL("MidiVid VQ"),
283  .type = AVMEDIA_TYPE_VIDEO,
284  .id = AV_CODEC_ID_MVDV,
285  .priv_data_size = sizeof(MidiVidContext),
286  .init = decode_init,
287  .decode = decode_frame,
288  .flush = decode_flush,
289  .close = decode_close,
290  .capabilities = AV_CODEC_CAP_DR1,
291  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
292 };
#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:48
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:308
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
static void flush(AVCodecContext *avctx)
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:71
misc image utilities
Memory handling functions.
static void skip_bits_long(GetBitContext *s, int n)
Skips the specified number of bits.
Definition: get_bits.h:291
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: packet.h:364
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:736
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size)
Same behaviour av_fast_malloc but the buffer has additional AV_INPUT_BUFFER_PADDING_SIZE at the end w...
Definition: utils.c:72
const char * key
AVCodec.
Definition: codec.h:190
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
void * av_calloc(size_t nmemb, size_t size)
Non-inlined equivalent of av_mallocz_array().
Definition: mem.c:245
AVCodec ff_mvdv_decoder
Definition: midivid.c:280
uint8_t
#define av_cold
Definition: attributes.h:88
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:190
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
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:456
uint8_t * data
Definition: packet.h:363
bitstream reader API header.
ptrdiff_t size
Definition: opengl_enc.c:100
uint8_t * skip
Definition: midivid.c:42
#define FFALIGN(x, a)
Definition: macros.h:48
#define av_log(a,...)
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
static av_cold int decode_close(AVCodecContext *avctx)
Definition: midivid.c:269
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
static const uint16_t mask[17]
Definition: lzw.c:38
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available...
Definition: decode.c:1986
#define s0
Definition: regdef.h:37
GLsizei GLsizei * length
Definition: opengl_enc.c:114
const char * name
Name of the codec implementation.
Definition: codec.h:197
common internal API header
GetByteContext gb
Definition: midivid.c:38
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:317
uint8_t * uncompressed
Definition: midivid.c:40
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:391
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: midivid.c:190
int width
picture width / height.
Definition: avcodec.h:699
#define s(width, name)
Definition: cbs_vp9.c:257
AVFrame * frame
Definition: midivid.c:44
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:192
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:339
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:677
main external API structure.
Definition: avcodec.h:526
static ptrdiff_t lzss_uncompress(MidiVidContext *s, GetByteContext *gb, uint8_t *dst, unsigned int size)
Definition: midivid.c:154
const uint8_t * buffer_start
Definition: bytestream.h:34
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
static void decode_flush(AVCodecContext *avctx)
Definition: midivid.c:262
#define s1
Definition: regdef.h:38
static int decode_mvdv(MidiVidContext *s, AVCodecContext *avctx, AVFrame *frame)
Definition: midivid.c:47
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:566
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:322
static int op(uint8_t **dst, const uint8_t *dst_end, GetByteContext *gb, int pixel, int count, int *x, int width, int linesize)
Perform decode operation.
Definition: anm.c:75
common internal api header.
#define flag(name)
Definition: cbs_av1.c:552
static av_cold int decode_init(AVCodecContext *avctx)
Definition: midivid.c:236
void * priv_data
Definition: avcodec.h:553
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:386
unsigned int uncompressed_size
Definition: midivid.c:41
#define av_freep(p)
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
This structure stores compressed data.
Definition: packet.h:340
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:50
int i
Definition: input.c:407
Predicted.
Definition: avutil.h:275