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1 /*
2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 // Decode With Partial Drops Example
12 // =========================
13 //
14 // This is an example utility which drops a series of frames (or parts of
15 // frames), as specified on the command line. This is useful for observing the
16 // error recovery features of the codec.
17 //
18 // Usage
19 // -----
20 // This example adds a single argument to the `simple_decoder` example,
21 // which specifies the range or pattern of frames to drop. The parameter is
22 // parsed as follows.
23 //
24 // Dropping A Range Of Frames
25 // --------------------------
26 // To drop a range of frames, specify the starting frame and the ending
27 // frame to drop, separated by a dash. The following command will drop
28 // frames 5 through 10 (base 1).
29 //
30 //  $ ./decode_with_partial_drops in.ivf out.i420 5-10
31 //
32 //
33 // Dropping A Pattern Of Frames
34 // ----------------------------
35 // To drop a pattern of frames, specify the number of frames to drop and
36 // the number of frames after which to repeat the pattern, separated by
37 // a forward-slash. The following command will drop 3 of 7 frames.
38 // Specifically, it will decode 4 frames, then drop 3 frames, and then
39 // repeat.
40 //
41 //  $ ./decode_with_partial_drops in.ivf out.i420 3/7
42 //
43 // Dropping Random Parts Of Frames
44 // -------------------------------
45 // A third argument tuple is available to split the frame into 1500 bytes pieces
46 // and randomly drop pieces rather than frames. The frame will be split at
47 // partition boundaries where possible. The following example will seed the RNG
48 // with the seed 123 and drop approximately 5% of the pieces. Pieces which
49 // are depending on an already dropped piece will also be dropped.
50 //
51 //  $ ./decode_with_partial_drops in.ivf out.i420 5,123
52 //
53 // Extra Variables
54 // ---------------
55 // This example maintains the pattern passed on the command line in the
56 // `n`, `m`, and `is_range` variables:
57 //
58 // Making The Drop Decision
59 // ------------------------
60 // The example decides whether to drop the frame based on the current
61 // frame number, immediately before decoding the frame.
62 
63 #include <stdarg.h>
64 #include <stdio.h>
65 #include <stdlib.h>
66 #include <string.h>
67 #define VPX_CODEC_DISABLE_COMPAT 1
68 #include "./vpx_config.h"
69 #include "vpx/vp8dx.h"
70 #include "vpx/vpx_decoder.h"
71 #define interface (vpx_codec_vp8_dx())
72 #include <time.h>
73 
74 
75 #define IVF_FILE_HDR_SZ  (32)
76 #define IVF_FRAME_HDR_SZ (12)
77 
mem_get_le32(const unsigned char * mem)78 static unsigned int mem_get_le32(const unsigned char *mem) {
79     return (mem[3] << 24)|(mem[2] << 16)|(mem[1] << 8)|(mem[0]);
80 }
81 
die(const char * fmt,...)82 static void die(const char *fmt, ...) {
83     va_list ap;
84 
85     va_start(ap, fmt);
86     vprintf(fmt, ap);
87     if(fmt[strlen(fmt)-1] != '\n')
88         printf("\n");
89     exit(EXIT_FAILURE);
90 }
91 
die_codec(vpx_codec_ctx_t * ctx,const char * s)92 static void die_codec(vpx_codec_ctx_t *ctx, const char *s) {
93     const char *detail = vpx_codec_error_detail(ctx);
94 
95     printf("%s: %s\n", s, vpx_codec_error(ctx));
96     if(detail)
97         printf("    %s\n",detail);
98     exit(EXIT_FAILURE);
99 }
100 
101 struct parsed_header
102 {
103     char key_frame;
104     int version;
105     char show_frame;
106     int first_part_size;
107 };
108 
next_packet(struct parsed_header * hdr,int pos,int length,int mtu)109 int next_packet(struct parsed_header* hdr, int pos, int length, int mtu)
110 {
111     int size = 0;
112     int remaining = length - pos;
113     /* Uncompressed part is 3 bytes for P frames and 10 bytes for I frames */
114     int uncomp_part_size = (hdr->key_frame ? 10 : 3);
115     /* number of bytes yet to send from header and the first partition */
116     int remainFirst = uncomp_part_size + hdr->first_part_size - pos;
117     if (remainFirst > 0)
118     {
119         if (remainFirst <= mtu)
120         {
121             size = remainFirst;
122         }
123         else
124         {
125             size = mtu;
126         }
127 
128         return size;
129     }
130 
131     /* second partition; just slot it up according to MTU */
132     if (remaining <= mtu)
133     {
134         size = remaining;
135         return size;
136     }
137     return mtu;
138 }
139 
throw_packets(unsigned char * frame,int * size,int loss_rate,int * thrown,int * kept)140 void throw_packets(unsigned char* frame, int* size, int loss_rate,
141                    int* thrown, int* kept)
142 {
143     unsigned char loss_frame[256*1024];
144     int pkg_size = 1;
145     int pos = 0;
146     int loss_pos = 0;
147     struct parsed_header hdr;
148     unsigned int tmp;
149     int mtu = 1500;
150 
151     if (*size < 3)
152     {
153         return;
154     }
155     putc('|', stdout);
156     /* parse uncompressed 3 bytes */
157     tmp = (frame[2] << 16) | (frame[1] << 8) | frame[0];
158     hdr.key_frame = !(tmp & 0x1); /* inverse logic */
159     hdr.version = (tmp >> 1) & 0x7;
160     hdr.show_frame = (tmp >> 4) & 0x1;
161     hdr.first_part_size = (tmp >> 5) & 0x7FFFF;
162 
163     /* don't drop key frames */
164     if (hdr.key_frame)
165     {
166         int i;
167         *kept = *size/mtu + ((*size % mtu > 0) ? 1 : 0); /* approximate */
168         for (i=0; i < *kept; i++)
169             putc('.', stdout);
170         return;
171     }
172 
173     while ((pkg_size = next_packet(&hdr, pos, *size, mtu)) > 0)
174     {
175         int loss_event = ((rand() + 1.0)/(RAND_MAX + 1.0) < loss_rate/100.0);
176         if (*thrown == 0 && !loss_event)
177         {
178             memcpy(loss_frame + loss_pos, frame + pos, pkg_size);
179             loss_pos += pkg_size;
180             (*kept)++;
181             putc('.', stdout);
182         }
183         else
184         {
185             (*thrown)++;
186             putc('X', stdout);
187         }
188         pos += pkg_size;
189     }
190     memcpy(frame, loss_frame, loss_pos);
191     memset(frame + loss_pos, 0, *size - loss_pos);
192     *size = loss_pos;
193 }
194 
main(int argc,char ** argv)195 int main(int argc, char **argv) {
196     FILE            *infile, *outfile;
197     vpx_codec_ctx_t  codec;
198     int              flags = 0, frame_cnt = 0;
199     unsigned char    file_hdr[IVF_FILE_HDR_SZ];
200     unsigned char    frame_hdr[IVF_FRAME_HDR_SZ];
201     unsigned char    frame[256*1024];
202     vpx_codec_err_t  res;
203     int              n, m, mode;
204     unsigned int     seed;
205     int              thrown=0, kept=0;
206     int              thrown_frame=0, kept_frame=0;
207     vpx_codec_dec_cfg_t  dec_cfg = {0};
208 
209     (void)res;
210     /* Open files */
211     if(argc < 4 || argc > 6)
212         die("Usage: %s <infile> <outfile> [-t <num threads>] <N-M|N/M|L,S>\n",
213             argv[0]);
214     {
215         char *nptr;
216         int arg_num = 3;
217         if (argc == 6 && strncmp(argv[arg_num++], "-t", 2) == 0)
218             dec_cfg.threads = strtol(argv[arg_num++], NULL, 0);
219         n = strtol(argv[arg_num], &nptr, 0);
220         mode = (*nptr == '\0' || *nptr == ',') ? 2 : (*nptr == '-') ? 1 : 0;
221 
222         m = strtol(nptr+1, NULL, 0);
223         if((!n && !m) || (*nptr != '-' && *nptr != '/' &&
224             *nptr != '\0' && *nptr != ','))
225             die("Couldn't parse pattern %s\n", argv[3]);
226     }
227     seed = (m > 0) ? m : (unsigned int)time(NULL);
228     srand(seed);thrown_frame = 0;
229     printf("Seed: %u\n", seed);
230     printf("Threads: %d\n", dec_cfg.threads);
231     if(!(infile = fopen(argv[1], "rb")))
232         die("Failed to open %s for reading", argv[1]);
233     if(!(outfile = fopen(argv[2], "wb")))
234         die("Failed to open %s for writing", argv[2]);
235 
236     /* Read file header */
237     if(!(fread(file_hdr, 1, IVF_FILE_HDR_SZ, infile) == IVF_FILE_HDR_SZ
238          && file_hdr[0]=='D' && file_hdr[1]=='K' && file_hdr[2]=='I'
239          && file_hdr[3]=='F'))
240         die("%s is not an IVF file.", argv[1]);
241 
242     printf("Using %s\n",vpx_codec_iface_name(interface));
243     /* Initialize codec */
244     flags = VPX_CODEC_USE_ERROR_CONCEALMENT;
245     res = vpx_codec_dec_init(&codec, interface, &dec_cfg, flags);
246     if(res)
247         die_codec(&codec, "Failed to initialize decoder");
248 
249 
250     /* Read each frame */
251     while(fread(frame_hdr, 1, IVF_FRAME_HDR_SZ, infile) == IVF_FRAME_HDR_SZ) {
252         int               frame_sz = mem_get_le32(frame_hdr);
253         vpx_codec_iter_t  iter = NULL;
254         vpx_image_t      *img;
255 
256 
257         frame_cnt++;
258         if(frame_sz > sizeof(frame))
259             die("Frame %d data too big for example code buffer", frame_sz);
260         if(fread(frame, 1, frame_sz, infile) != frame_sz)
261             die("Frame %d failed to read complete frame", frame_cnt);
262 
263         /* Decide whether to throw parts of the frame or the whole frame
264            depending on the drop mode */
265         thrown_frame = 0;
266         kept_frame = 0;
267         switch (mode)
268         {
269         case 0:
270             if (m - (frame_cnt-1)%m <= n)
271             {
272                 frame_sz = 0;
273             }
274             break;
275         case 1:
276             if (frame_cnt >= n && frame_cnt <= m)
277             {
278                 frame_sz = 0;
279             }
280             break;
281         case 2:
282             throw_packets(frame, &frame_sz, n, &thrown_frame, &kept_frame);
283             break;
284         default: break;
285         }
286         if (mode < 2)
287         {
288             if (frame_sz == 0)
289             {
290                 putc('X', stdout);
291                 thrown_frame++;
292             }
293             else
294             {
295                 putc('.', stdout);
296                 kept_frame++;
297             }
298         }
299         thrown += thrown_frame;
300         kept += kept_frame;
301         fflush(stdout);
302         /* Decode the frame */
303         if(vpx_codec_decode(&codec, frame, frame_sz, NULL, 0))
304             die_codec(&codec, "Failed to decode frame");
305 
306         /* Write decoded data to disk */
307         while((img = vpx_codec_get_frame(&codec, &iter))) {
308             unsigned int plane, y;
309 
310             for(plane=0; plane < 3; plane++) {
311                 unsigned char *buf =img->planes[plane];
312 
313                 for(y=0; y < (plane ? (img->d_h + 1) >> 1 : img->d_h); y++) {
314                     (void) fwrite(buf, 1, (plane ? (img->d_w + 1) >> 1 : img->d_w),
315                                   outfile);
316                     buf += img->stride[plane];
317                 }
318             }
319         }
320     }
321     printf("Processed %d frames.\n",frame_cnt);
322     if(vpx_codec_destroy(&codec))
323         die_codec(&codec, "Failed to destroy codec");
324 
325     fclose(outfile);
326     fclose(infile);
327     return EXIT_SUCCESS;
328 }
329