examples/simple_encoder.c

   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 // Simple Encoder
  12 // ==============
  13 //
  14 // This is an example of a simple encoder loop. It takes an input file in
  15 // YV12 format, passes it through the encoder, and writes the compressed
  16 // frames to disk in IVF format. Other decoder examples build upon this
  17 // one.
  18 //
  19 // The details of the IVF format have been elided from this example for
  20 // simplicity of presentation, as IVF files will not generally be used by
  21 // your application. In general, an IVF file consists of a file header,
  22 // followed by a variable number of frames. Each frame consists of a frame
  23 // header followed by a variable length payload. The length of the payload
  24 // is specified in the first four bytes of the frame header. The payload is
  25 // the raw compressed data.
  26 //
  27 // Standard Includes
  28 // -----------------
  29 // For encoders, you only have to include `vpx_encoder.h` and then any
  30 // header files for the specific codecs you use. In this case, we're using
  31 // vp8.
  32 //
  33 // Getting The Default Configuration
  34 // ---------------------------------
  35 // Encoders have the notion of "usage profiles." For example, an encoder
  36 // may want to publish default configurations for both a video
  37 // conferencing application and a best quality offline encoder. These
  38 // obviously have very different default settings. Consult the
  39 // documentation for your codec to see if it provides any default
  40 // configurations. All codecs provide a default configuration, number 0,
  41 // which is valid for material in the vacinity of QCIF/QVGA.
  42 //
  43 // Updating The Configuration
  44 // ---------------------------------
  45 // Almost all applications will want to update the default configuration
  46 // with settings specific to their usage. Here we set the width and height
  47 // of the video file to that specified on the command line. We also scale
  48 // the default bitrate based on the ratio between the default resolution
  49 // and the resolution specified on the command line.
  50 //
  51 // Initializing The Codec
  52 // ----------------------
  53 // The encoder is initialized by the following code.
  54 //
  55 // Encoding A Frame
  56 // ----------------
  57 // The frame is read as a continuous block (size width * height * 3 / 2)
  58 // from the input file. If a frame was read (the input file has not hit
  59 // EOF) then the frame is passed to the encoder. Otherwise, a NULL
  60 // is passed, indicating the End-Of-Stream condition to the encoder. The
  61 // `frame_cnt` is reused as the presentation time stamp (PTS) and each
  62 // frame is shown for one frame-time in duration. The flags parameter is
  63 // unused in this example. The deadline is set to VPX_DL_REALTIME to
  64 // make the example run as quickly as possible.
  65
  66 // Forced Keyframes
  67 // ----------------
  68 // Keyframes can be forced by setting the VPX_EFLAG_FORCE_KF bit of the
  69 // flags passed to `vpx_codec_control()`. In this example, we force a
  70 // keyframe every <keyframe-interval> frames. Note, the output stream can
  71 // contain additional keyframes beyond those that have been forced using the
  72 // VPX_EFLAG_FORCE_KF flag because of automatic keyframe placement by the
  73 // encoder.
  74 //
  75 // Processing The Encoded Data
  76 // ---------------------------
  77 // Each packet of type `VPX_CODEC_CX_FRAME_PKT` contains the encoded data
  78 // for this frame. We write a IVF frame header, followed by the raw data.
  79 //
  80 // Cleanup
  81 // -------
  82 // The `vpx_codec_destroy` call frees any memory allocated by the codec.
  83 //
  84 // Error Handling
  85 // --------------
  86 // This example does not special case any error return codes. If there was
  87 // an error, a descriptive message is printed and the program exits. With
  88 // few exeptions, vpx_codec functions return an enumerated error status,
  89 // with the value `0` indicating success.
  90 //
  91 // Error Resiliency Features
  92 // -------------------------
  93 // Error resiliency is controlled by the g_error_resilient member of the
  94 // configuration structure. Use the `decode_with_drops` example to decode with
  95 // frames 5-10 dropped. Compare the output for a file encoded with this example
  96 // versus one encoded with the `simple_encoder` example.
  97
  98 #include <stdio.h>
  99 #include <stdlib.h>
 100 #include <string.h>
 101
 102 #include "vpx/vpx_encoder.h"
 103
 104 #include "../tools_common.h"
 105 #include "../video_writer.h"
 106
 107 static const char *exec_name;
 108
 109 void usage_exit(void) {
 110   fprintf(stderr,
 111           "Usage: %s <codec> <width> <height> <infile> <outfile> "
 112               "<keyframe-interval> [<error-resilient>]\nSee comments in "
 113               "simple_encoder.c for more information.\n",
 114           exec_name);
 115   exit(EXIT_FAILURE);
 116 }
 117
 118 static int encode_frame(vpx_codec_ctx_t *codec,
 119                         vpx_image_t *img,
 120                         int frame_index,
 121                         int flags,
 122                         VpxVideoWriter *writer) {
 123   int got_pkts = 0;
 124   vpx_codec_iter_t iter = NULL;
 125   const vpx_codec_cx_pkt_t *pkt = NULL;
 126   const vpx_codec_err_t res = vpx_codec_encode(codec, img, frame_index, 1,
 127                                                flags, VPX_DL_GOOD_QUALITY);
 128   if (res != VPX_CODEC_OK)
 129     die_codec(codec, "Failed to encode frame");
 130
 131   while ((pkt = vpx_codec_get_cx_data(codec, &iter)) != NULL) {
 132     got_pkts = 1;
 133
 134     if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
 135       const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
 136       if (!vpx_video_writer_write_frame(writer,
 137                                         pkt->data.frame.buf,
 138                                         pkt->data.frame.sz,
 139                                         pkt->data.frame.pts)) {
 140         die_codec(codec, "Failed to write compressed frame");
 141       }
 142       printf(keyframe ? "K" : ".");
 143       fflush(stdout);
 144     }
 145   }
 146
 147   return got_pkts;
 148 }
 149
 150 int main(int argc, char **argv) {
 151   FILE *infile = NULL;
 152   vpx_codec_ctx_t codec;
 153   vpx_codec_enc_cfg_t cfg;
 154   int frame_count = 0;
 155   vpx_image_t raw;
 156   vpx_codec_err_t res;
 157   VpxVideoInfo info = {0};
 158   VpxVideoWriter *writer = NULL;
 159   const VpxInterface *encoder = NULL;
 160   const int fps = 30;        // TODO(dkovalev) add command line argument
 161   const int bitrate = 200;   // kbit/s TODO(dkovalev) add command line argument
 162   int keyframe_interval = 0;
 163
 164   // TODO(dkovalev): Add some simple command line parsing code to make the
 165   // command line more flexible.
 166   const char *codec_arg = NULL;
 167   const char *width_arg = NULL;
 168   const char *height_arg = NULL;
 169   const char *infile_arg = NULL;
 170   const char *outfile_arg = NULL;
 171   const char *keyframe_interval_arg = NULL;
 172
 173   exec_name = argv[0];
 174
 175   if (argc < 7)
 176     die("Invalid number of arguments");
 177
 178   codec_arg = argv[1];
 179   width_arg = argv[2];
 180   height_arg = argv[3];
 181   infile_arg = argv[4];
 182   outfile_arg = argv[5];
 183   keyframe_interval_arg = argv[6];
 184
 185   encoder = get_vpx_encoder_by_name(codec_arg);
 186   if (!encoder)
 187      die("Unsupported codec.");
 188
 189   info.codec_fourcc = encoder->fourcc;
 190   info.frame_width = strtol(width_arg, NULL, 0);
 191   info.frame_height = strtol(height_arg, NULL, 0);
 192   info.time_base.numerator = 1;
 193   info.time_base.denominator = fps;
 194
 195   if (info.frame_width <= 0 ||
 196       info.frame_height <= 0 ||
 197       (info.frame_width % 2) != 0 ||
 198       (info.frame_height % 2) != 0) {
 199     die("Invalid frame size: %dx%d", info.frame_width, info.frame_height);
 200   }
 201
 202   if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, info.frame_width,
 203                                              info.frame_height, 1)) {
 204     die("Failed to allocate image.");
 205   }
 206
 207   keyframe_interval = strtol(keyframe_interval_arg, NULL, 0);
 208   if (keyframe_interval < 0)
 209     die("Invalid keyframe interval value.");
 210
 211   printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
 212
 213   res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);
 214   if (res)
 215     die_codec(&codec, "Failed to get default codec config.");
 216
 217   cfg.g_w = info.frame_width;
 218   cfg.g_h = info.frame_height;
 219   cfg.g_timebase.num = info.time_base.numerator;
 220   cfg.g_timebase.den = info.time_base.denominator;
 221   cfg.rc_target_bitrate = bitrate;
 222   cfg.g_error_resilient = argc > 7 ? strtol(argv[7], NULL, 0) : 0;
 223
 224   writer = vpx_video_writer_open(outfile_arg, kContainerIVF, &info);
 225   if (!writer)
 226     die("Failed to open %s for writing.", outfile_arg);
 227
 228   if (!(infile = fopen(infile_arg, "rb")))
 229     die("Failed to open %s for reading.", infile_arg);
 230
 231   if (vpx_codec_enc_init(&codec, encoder->codec_interface(), &cfg, 0))
 232     die_codec(&codec, "Failed to initialize encoder");
 233
 234   // Encode frames.
 235   while (vpx_img_read(&raw, infile)) {
 236     int flags = 0;
 237     if (keyframe_interval > 0 && frame_count % keyframe_interval == 0)
 238       flags |= VPX_EFLAG_FORCE_KF;
 239     encode_frame(&codec, &raw, frame_count++, flags, writer);
 240   }
 241
 242   // Flush encoder.
 243   while (encode_frame(&codec, NULL, -1, 0, writer)) {};
 244
 245   printf("\n");
 246   fclose(infile);
 247   printf("Processed %d frames.\n", frame_count);
 248
 249   vpx_img_free(&raw);
 250   if (vpx_codec_destroy(&codec))
 251     die_codec(&codec, "Failed to destroy codec.");
 252
 253   vpx_video_writer_close(writer);
 254
 255   return EXIT_SUCCESS;
 256 }