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 "libavutil/imgutils.h"
23 #include "libavutil/internal.h"
24 #include "libavutil/mem.h"
25 
26 #define BITSTREAM_READER_LE
27 #include "avcodec.h"
28 #include "get_bits.h"
29 #include "bytestream.h"
30 #include "codec_internal.h"
31 #include "decode.h"
32 
33 typedef struct MidiVidContext {
35 
36  uint8_t *uncompressed;
37  unsigned int uncompressed_size;
38  uint8_t *skip;
39 
42 
44 {
45  GetByteContext *gb = &s->gb;
47  GetByteContext idx9;
48  uint16_t nb_vectors, intra_flag;
49  const uint8_t *vec;
50  const uint8_t *mask_start;
51  uint8_t *skip;
52  uint32_t mask_size;
53  int idx9bits = 0;
54  int idx9val = 0;
55  uint32_t nb_blocks;
56 
57  nb_vectors = bytestream2_get_le16(gb);
58  intra_flag = !!bytestream2_get_le16(gb);
59  if (intra_flag) {
60  nb_blocks = (avctx->width / 2) * (avctx->height / 2);
61  } else {
62  int ret, skip_linesize, padding;
63 
64  nb_blocks = bytestream2_get_le32(gb);
65  skip_linesize = avctx->width >> 1;
66  mask_start = gb->buffer_start + bytestream2_tell(gb);
67  mask_size = (FFALIGN(avctx->width, 32) >> 2) * (avctx->height >> 2) >> 3;
68  padding = (FFALIGN(avctx->width, 32) - avctx->width) >> 2;
69 
70  if (bytestream2_get_bytes_left(gb) < mask_size)
71  return AVERROR_INVALIDDATA;
72 
73  ret = init_get_bits8(&mask, mask_start, mask_size);
74  if (ret < 0)
75  return ret;
76  bytestream2_skip(gb, mask_size);
77  skip = s->skip;
78 
79  for (int y = 0; y < avctx->height >> 2; y++) {
80  for (int x = 0; x < avctx->width >> 2; x++) {
81  int flag = !get_bits1(&mask);
82 
83  skip[(y*2) *skip_linesize + x*2 ] = flag;
84  skip[(y*2) *skip_linesize + x*2+1] = flag;
85  skip[(y*2+1)*skip_linesize + x*2 ] = flag;
86  skip[(y*2+1)*skip_linesize + x*2+1] = flag;
87  }
88  skip_bits_long(&mask, padding);
89  }
90  }
91 
92  vec = gb->buffer_start + bytestream2_tell(gb);
93  if (bytestream2_get_bytes_left(gb) < nb_vectors * 12)
94  return AVERROR_INVALIDDATA;
95  bytestream2_skip(gb, nb_vectors * 12);
96  if (nb_vectors > 256) {
97  if (bytestream2_get_bytes_left(gb) < (nb_blocks + 7 * !intra_flag) / 8)
98  return AVERROR_INVALIDDATA;
99  bytestream2_init(&idx9, gb->buffer_start + bytestream2_tell(gb), (nb_blocks + 7 * !intra_flag) / 8);
100  bytestream2_skip(gb, (nb_blocks + 7 * !intra_flag) / 8);
101  }
102 
103  skip = s->skip;
104 
105  for (int y = avctx->height - 2; y >= 0; y -= 2) {
106  uint8_t *dsty = frame->data[0] + y * frame->linesize[0];
107  uint8_t *dstu = frame->data[1] + y * frame->linesize[1];
108  uint8_t *dstv = frame->data[2] + y * frame->linesize[2];
109 
110  for (int x = 0; x < avctx->width; x += 2) {
111  int idx;
112 
113  if (!intra_flag && *skip++)
114  continue;
115  if (bytestream2_get_bytes_left(gb) <= 0)
116  return AVERROR_INVALIDDATA;
117  if (nb_vectors <= 256) {
118  idx = bytestream2_get_byte(gb);
119  } else {
120  if (idx9bits == 0) {
121  idx9val = bytestream2_get_byte(&idx9);
122  idx9bits = 8;
123  }
124  idx9bits--;
125  idx = bytestream2_get_byte(gb) | (((idx9val >> (7 - idx9bits)) & 1) << 8);
126  }
127  if (idx >= nb_vectors)
128  return AVERROR_INVALIDDATA;
129 
130  dsty[x +frame->linesize[0]] = vec[idx * 12 + 0];
131  dsty[x+1+frame->linesize[0]] = vec[idx * 12 + 3];
132  dsty[x] = vec[idx * 12 + 6];
133  dsty[x+1] = vec[idx * 12 + 9];
134 
135  dstu[x +frame->linesize[1]] = vec[idx * 12 + 1];
136  dstu[x+1+frame->linesize[1]] = vec[idx * 12 + 4];
137  dstu[x] = vec[idx * 12 + 7];
138  dstu[x+1] = vec[idx * 12 +10];
139 
140  dstv[x +frame->linesize[2]] = vec[idx * 12 + 2];
141  dstv[x+1+frame->linesize[2]] = vec[idx * 12 + 5];
142  dstv[x] = vec[idx * 12 + 8];
143  dstv[x+1] = vec[idx * 12 +11];
144  }
145  }
146 
147  return intra_flag;
148 }
149 
150 static ptrdiff_t lzss_uncompress(MidiVidContext *s, GetByteContext *gb, uint8_t *dst, unsigned int size)
151 {
152  uint8_t *dst_start = dst;
153  uint8_t *dst_end = dst + size;
154 
155  for (;bytestream2_get_bytes_left(gb) >= 3;) {
156  int op = bytestream2_get_le16(gb);
157 
158  for (int i = 0; i < 16; i++) {
159  if (op & 1) {
160  int s0 = bytestream2_get_byte(gb);
161  int s1 = bytestream2_get_byte(gb);
162  int offset = ((s0 & 0xF0) << 4) | s1;
163  int length = (s0 & 0xF) + 3;
164 
165  if (dst + length > dst_end ||
166  dst - offset < dst_start)
167  return AVERROR_INVALIDDATA;
168  if (offset > 0) {
169  for (int j = 0; j < length; j++) {
170  dst[j] = dst[j - offset];
171  }
172  }
173  dst += length;
174  } else {
175  if (dst >= dst_end)
176  return AVERROR_INVALIDDATA;
177  *dst++ = bytestream2_get_byte(gb);
178  }
179  op >>= 1;
180  }
181  }
182 
183  return dst - dst_start;
184 }
185 
186 static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
187  int *got_frame, AVPacket *avpkt)
188 {
189  MidiVidContext *s = avctx->priv_data;
190  GetByteContext *gb = &s->gb;
191  AVFrame *frame = s->frame;
192  int ret, key, uncompressed;
193 
194  if (avpkt->size <= 13)
195  return AVERROR_INVALIDDATA;
196 
197  bytestream2_init(gb, avpkt->data, avpkt->size);
198  bytestream2_skip(gb, 8);
199  uncompressed = bytestream2_get_le32(gb);
200 
201  if (!uncompressed) {
202  av_fast_padded_malloc(&s->uncompressed, &s->uncompressed_size, 16LL * (avpkt->size - 12));
203  if (!s->uncompressed)
204  return AVERROR(ENOMEM);
205 
206  ret = lzss_uncompress(s, gb, s->uncompressed, s->uncompressed_size);
207  if (ret < 0)
208  return ret;
209  bytestream2_init(gb, s->uncompressed, ret);
210  }
211 
212  if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
213  return ret;
214 
215  ret = decode_mvdv(s, avctx, frame);
216 
217  if (ret < 0)
218  return ret;
219  key = ret;
220 
221  if ((ret = av_frame_ref(rframe, s->frame)) < 0)
222  return ret;
223 
224  frame->pict_type = key ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
225  frame->key_frame = key;
226  *got_frame = 1;
227 
228  return avpkt->size;
229 }
230 
232 {
233  MidiVidContext *s = avctx->priv_data;
234  int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
235 
236  if (avctx->width & 3 || avctx->height & 3)
238 
239  if (ret < 0) {
240  av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
241  avctx->width, avctx->height);
242  return ret;
243  }
244 
245  avctx->pix_fmt = AV_PIX_FMT_YUV444P;
246 
247  s->frame = av_frame_alloc();
248  if (!s->frame)
249  return AVERROR(ENOMEM);
250  s->skip = av_calloc(avctx->width >> 1, avctx->height >> 1);
251  if (!s->skip)
252  return AVERROR(ENOMEM);
253 
254  return 0;
255 }
256 
257 static void decode_flush(AVCodecContext *avctx)
258 {
259  MidiVidContext *s = avctx->priv_data;
260 
261  av_frame_unref(s->frame);
262 }
263 
265 {
266  MidiVidContext *s = avctx->priv_data;
267 
268  av_frame_free(&s->frame);
269  av_freep(&s->uncompressed);
270  av_freep(&s->skip);
271 
272  return 0;
273 }
274 
276  .p.name = "mvdv",
277  CODEC_LONG_NAME("MidiVid VQ"),
278  .p.type = AVMEDIA_TYPE_VIDEO,
279  .p.id = AV_CODEC_ID_MVDV,
280  .priv_data_size = sizeof(MidiVidContext),
281  .init = decode_init,
283  .flush = decode_flush,
284  .close = decode_close,
285  .p.capabilities = AV_CODEC_CAP_DR1,
286  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
287 };
skip_bits_long
static void skip_bits_long(GetBitContext *s, int n)
Skips the specified number of bits.
Definition: get_bits.h:291
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
GetByteContext::buffer_start
const uint8_t * buffer_start
Definition: bytestream.h:34
GetByteContext
Definition: bytestream.h:33
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:116
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AVPacket::data
uint8_t * data
Definition: packet.h:374
FFCodec
Definition: codec_internal.h:119
MidiVidContext
Definition: midivid.c:33
MidiVidContext::uncompressed
uint8_t * uncompressed
Definition: midivid.c:36
decode_close
static av_cold int decode_close(AVCodecContext *avctx)
Definition: midivid.c:264
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:123
GetBitContext
Definition: get_bits.h:61
MidiVidContext::frame
AVFrame * frame
Definition: midivid.c:40
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:104
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
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:667
mask
static const uint16_t mask[17]
Definition: lzw.c:38
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:298
s
#define s(width, name)
Definition: cbs_vp9.c:256
op
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:76
s1
#define s1
Definition: regdef.h:38
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts_bsf.c:363
decode.h
get_bits.h
key
const char * key
Definition: hwcontext_opencl.c:174
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:264
MidiVidContext::gb
GetByteContext gb
Definition: midivid.c:34
AV_CODEC_ID_MVDV
@ AV_CODEC_ID_MVDV
Definition: codec_id.h:301
MidiVidContext::skip
uint8_t * skip
Definition: midivid.c:38
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
get_bits1
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
bytestream2_tell
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:192
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:375
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:353
codec_internal.h
size
int size
Definition: twinvq_data.h:10344
lzss_uncompress
static ptrdiff_t lzss_uncompress(MidiVidContext *s, GetByteContext *gb, uint8_t *dst, unsigned int size)
Definition: midivid.c:150
offset
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
Definition: writing_filters.txt:86
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)
Definition: midivid.c:186
flag
#define flag(name)
Definition: cbs_av1.c:553
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
internal.h
av_fast_padded_malloc
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: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:487
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
AVCodecContext::height
int height
Definition: avcodec.h:571
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
av_calloc
void * av_calloc(size_t nmemb, size_t size)
Definition: mem.c:272
avcodec.h
ff_reget_buffer
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:1568
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
decode_mvdv
static int decode_mvdv(MidiVidContext *s, AVCodecContext *avctx, AVFrame *frame)
Definition: midivid.c:43
AVCodecContext
main external API structure.
Definition: avcodec.h:398
decode_flush
static void decode_flush(AVCodecContext *avctx)
Definition: midivid.c:257
AV_PIX_FMT_YUV444P
@ AV_PIX_FMT_YUV444P
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:71
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:275
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
mem.h
s0
#define s0
Definition: regdef.h:37
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: midivid.c:231
FFALIGN
#define FFALIGN(x, a)
Definition: macros.h:78
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:425
AVPacket
This structure stores compressed data.
Definition: packet.h:351
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:571
bytestream.h
imgutils.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_mvdv_decoder
const FFCodec ff_mvdv_decoder
Definition: midivid.c:275
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
MidiVidContext::uncompressed_size
unsigned int uncompressed_size
Definition: midivid.c:37