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
78static unsigned int mem_get_le32(const unsigned char *mem) {
79    return (mem[3] << 24)|(mem[2] << 16)|(mem[1] << 8)|(mem[0]);
80}
81
82static 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
92static 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
101struct parsed_header
102{
103    char key_frame;
104    int version;
105    char show_frame;
106    int first_part_size;
107};
108
109int 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
140void 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
195int 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