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      1 /*
      2  * Copyright (c) 2016, Alliance for Open Media. All rights reserved
      3  *
      4  * This source code is subject to the terms of the BSD 2 Clause License and
      5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
      6  * was not distributed with this source code in the LICENSE file, you can
      7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
      8  * Media Patent License 1.0 was not distributed with this source code in the
      9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
     10  */
     11 
     12 // Decode With Drops Example
     13 // =========================
     14 //
     15 // This is an example utility which drops a series of frames, as specified
     16 // on the command line. This is useful for observing the error recovery
     17 // features of the codec.
     18 //
     19 // Usage
     20 // -----
     21 // This example adds a single argument to the `simple_decoder` example,
     22 // which specifies the range or pattern of frames to drop. The parameter is
     23 // parsed as follows:
     24 //
     25 // Dropping A Range Of Frames
     26 // --------------------------
     27 // To drop a range of frames, specify the starting frame and the ending
     28 // frame to drop, separated by a dash. The following command will drop
     29 // frames 5 through 10 (base 1).
     30 //
     31 //  $ ./decode_with_drops in.ivf out.i420 5-10
     32 //
     33 //
     34 // Dropping A Pattern Of Frames
     35 // ----------------------------
     36 // To drop a pattern of frames, specify the number of frames to drop and
     37 // the number of frames after which to repeat the pattern, separated by
     38 // a forward-slash. The following command will drop 3 of 7 frames.
     39 // Specifically, it will decode 4 frames, then drop 3 frames, and then
     40 // repeat.
     41 //
     42 //  $ ./decode_with_drops in.ivf out.i420 3/7
     43 //
     44 //
     45 // Extra Variables
     46 // ---------------
     47 // This example maintains the pattern passed on the command line in the
     48 // `n`, `m`, and `is_range` variables:
     49 //
     50 //
     51 // Making The Drop Decision
     52 // ------------------------
     53 // The example decides whether to drop the frame based on the current
     54 // frame number, immediately before decoding the frame.
     55 
     56 #include <stdio.h>
     57 #include <stdlib.h>
     58 #include <string.h>
     59 
     60 #include "aom/aom_decoder.h"
     61 #include "aom/aomdx.h"
     62 #include "common/tools_common.h"
     63 #include "common/video_reader.h"
     64 
     65 static const char *exec_name;
     66 
     67 void usage_exit(void) {
     68   fprintf(stderr, "Usage: %s <infile> <outfile> <N-M|N/M>\n", exec_name);
     69   exit(EXIT_FAILURE);
     70 }
     71 
     72 int main(int argc, char **argv) {
     73   int frame_cnt = 0;
     74   FILE *outfile = NULL;
     75   aom_codec_ctx_t codec;
     76   const AvxInterface *decoder = NULL;
     77   AvxVideoReader *reader = NULL;
     78   const AvxVideoInfo *info = NULL;
     79   int n = 0;
     80   int m = 0;
     81   int is_range = 0;
     82   char *nptr = NULL;
     83 
     84   exec_name = argv[0];
     85 
     86   if (argc != 4) die("Invalid number of arguments.");
     87 
     88   reader = aom_video_reader_open(argv[1]);
     89   if (!reader) die("Failed to open %s for reading.", argv[1]);
     90 
     91   if (!(outfile = fopen(argv[2], "wb")))
     92     die("Failed to open %s for writing.", argv[2]);
     93 
     94   n = (int)strtol(argv[3], &nptr, 0);
     95   m = (int)strtol(nptr + 1, NULL, 0);
     96   is_range = (*nptr == '-');
     97   if (!n || !m || (*nptr != '-' && *nptr != '/'))
     98     die("Couldn't parse pattern %s.\n", argv[3]);
     99 
    100   info = aom_video_reader_get_info(reader);
    101 
    102   decoder = get_aom_decoder_by_fourcc(info->codec_fourcc);
    103   if (!decoder) die("Unknown input codec.");
    104 
    105   printf("Using %s\n", aom_codec_iface_name(decoder->codec_interface()));
    106 
    107   if (aom_codec_dec_init(&codec, decoder->codec_interface(), NULL, 0))
    108     die_codec(&codec, "Failed to initialize decoder.");
    109 
    110   while (aom_video_reader_read_frame(reader)) {
    111     aom_codec_iter_t iter = NULL;
    112     aom_image_t *img = NULL;
    113     size_t frame_size = 0;
    114     int skip;
    115     const unsigned char *frame =
    116         aom_video_reader_get_frame(reader, &frame_size);
    117     ++frame_cnt;
    118 
    119     skip = (is_range && frame_cnt >= n && frame_cnt <= m) ||
    120            (!is_range && m - (frame_cnt - 1) % m <= n);
    121 
    122     if (!skip) {
    123       putc('.', stdout);
    124       if (aom_codec_decode(&codec, frame, frame_size, NULL))
    125         die_codec(&codec, "Failed to decode frame.");
    126 
    127       while ((img = aom_codec_get_frame(&codec, &iter)) != NULL)
    128         aom_img_write(img, outfile);
    129     } else {
    130       putc('X', stdout);
    131     }
    132 
    133     fflush(stdout);
    134   }
    135 
    136   printf("Processed %d frames.\n", frame_cnt);
    137   if (aom_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
    138 
    139   printf("Play: ffplay -f rawvideo -pix_fmt yuv420p -s %dx%d %s\n",
    140          info->frame_width, info->frame_height, argv[2]);
    141 
    142   aom_video_reader_close(reader);
    143   fclose(outfile);
    144 
    145   return EXIT_SUCCESS;
    146 }
    147