examples/twopass_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 // Two Pass Encoder
  12 // ================
  13 //
  14 // This is an example of a two pass encoder loop. It takes an input file in
  15 // YV12 format, passes it through the encoder twice, and writes the compressed
  16 // frames to disk in IVF format. It builds upon the simple_encoder example.
  17 //
  18 // Twopass Variables
  19 // -----------------
  20 // Twopass mode needs to track the current pass number and the buffer of
  21 // statistics packets.
  22 //
  23 // Updating The Configuration
  24 // ---------------------------------
  25 // In two pass mode, the configuration has to be updated on each pass. The
  26 // statistics buffer is passed on the last pass.
  27 //
  28 // Encoding A Frame
  29 // ----------------
  30 // Encoding a frame in two pass mode is identical to the simple encoder
  31 // example. To increase the quality while sacrificing encoding speed,
  32 // VPX_DL_BEST_QUALITY can be used in place of VPX_DL_GOOD_QUALITY.
  33 //
  34 // Processing Statistics Packets
  35 // -----------------------------
  36 // Each packet of type `VPX_CODEC_CX_FRAME_PKT` contains the encoded data
  37 // for this frame. We write a IVF frame header, followed by the raw data.
  38 //
  39 //
  40 // Pass Progress Reporting
  41 // -----------------------------
  42 // It's sometimes helpful to see when each pass completes.
  43 //
  44 //
  45 // Clean-up
  46 // -----------------------------
  47 // Destruction of the encoder instance must be done on each pass. The
  48 // raw image should be destroyed at the end as usual.
  49
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53
  54 #include "vpx/vpx_encoder.h"
  55
  56 #include "../tools_common.h"
  57 #include "../video_writer.h"
  58
  59 static const char *exec_name;
  60
  61 void usage_exit(void) {
  62   fprintf(stderr, "Usage: %s <codec> <width> <height> <infile> <outfile>\n",
  63           exec_name);
  64   exit(EXIT_FAILURE);
  65 }
  66
  67 static int get_frame_stats(vpx_codec_ctx_t *ctx,
  68                            const vpx_image_t *img,
  69                            vpx_codec_pts_t pts,
  70                            unsigned int duration,
  71                            vpx_enc_frame_flags_t flags,
  72                            unsigned int deadline,
  73                            vpx_fixed_buf_t *stats) {
  74   int got_pkts = 0;
  75   vpx_codec_iter_t iter = NULL;
  76   const vpx_codec_cx_pkt_t *pkt = NULL;
  77   const vpx_codec_err_t res = vpx_codec_encode(ctx, img, pts, duration, flags,
  78                                                deadline);
  79   if (res != VPX_CODEC_OK)
  80     die_codec(ctx, "Failed to get frame stats.");
  81
  82   while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) {
  83     got_pkts = 1;
  84
  85     if (pkt->kind == VPX_CODEC_STATS_PKT) {
  86       const uint8_t *const pkt_buf = pkt->data.twopass_stats.buf;
  87       const size_t pkt_size = pkt->data.twopass_stats.sz;
  88       stats->buf = realloc(stats->buf, stats->sz + pkt_size);
  89       memcpy((uint8_t *)stats->buf + stats->sz, pkt_buf, pkt_size);
  90       stats->sz += pkt_size;
  91     }
  92   }
  93
  94   return got_pkts;
  95 }
  96
  97 static int encode_frame(vpx_codec_ctx_t *ctx,
  98                         const vpx_image_t *img,
  99                         vpx_codec_pts_t pts,
 100                         unsigned int duration,
 101                         vpx_enc_frame_flags_t flags,
 102                         unsigned int deadline,
 103                         VpxVideoWriter *writer) {
 104   int got_pkts = 0;
 105   vpx_codec_iter_t iter = NULL;
 106   const vpx_codec_cx_pkt_t *pkt = NULL;
 107   const vpx_codec_err_t res = vpx_codec_encode(ctx, img, pts, duration, flags,
 108                                                deadline);
 109   if (res != VPX_CODEC_OK)
 110     die_codec(ctx, "Failed to encode frame.");
 111
 112   while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) {
 113     got_pkts = 1;
 114     if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
 115       const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
 116
 117       if (!vpx_video_writer_write_frame(writer, pkt->data.frame.buf,
 118                                                 pkt->data.frame.sz,
 119                                                 pkt->data.frame.pts))
 120         die_codec(ctx, "Failed to write compressed frame.");
 121       printf(keyframe ? "K" : ".");
 122       fflush(stdout);
 123     }
 124   }
 125
 126   return got_pkts;
 127 }
 128
 129 static vpx_fixed_buf_t pass0(vpx_image_t *raw,
 130                              FILE *infile,
 131                              const VpxInterface *encoder,
 132                              const vpx_codec_enc_cfg_t *cfg) {
 133   vpx_codec_ctx_t codec;
 134   int frame_count = 0;
 135   vpx_fixed_buf_t stats = {NULL, 0};
 136
 137   if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0))
 138     die_codec(&codec, "Failed to initialize encoder");
 139
 140   // Calculate frame statistics.
 141   while (vpx_img_read(raw, infile)) {
 142     ++frame_count;
 143     get_frame_stats(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY,
 144                     &stats);
 145   }
 146
 147   // Flush encoder.
 148   while (get_frame_stats(&codec, NULL, frame_count, 1, 0,
 149                          VPX_DL_GOOD_QUALITY, &stats)) {}
 150
 151   printf("Pass 0 complete. Processed %d frames.\n", frame_count);
 152   if (vpx_codec_destroy(&codec))
 153     die_codec(&codec, "Failed to destroy codec.");
 154
 155   return stats;
 156 }
 157
 158 static void pass1(vpx_image_t *raw,
 159                   FILE *infile,
 160                   const char *outfile_name,
 161                   const VpxInterface *encoder,
 162                   const vpx_codec_enc_cfg_t *cfg) {
 163   VpxVideoInfo info = {
 164     encoder->fourcc,
 165     cfg->g_w,
 166     cfg->g_h,
 167     {cfg->g_timebase.num, cfg->g_timebase.den}
 168   };
 169   VpxVideoWriter *writer = NULL;
 170   vpx_codec_ctx_t codec;
 171   int frame_count = 0;
 172
 173   writer = vpx_video_writer_open(outfile_name, kContainerIVF, &info);
 174   if (!writer)
 175     die("Failed to open %s for writing", outfile_name);
 176
 177   if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0))
 178     die_codec(&codec, "Failed to initialize encoder");
 179
 180   // Encode frames.
 181   while (vpx_img_read(raw, infile)) {
 182     ++frame_count;
 183     encode_frame(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY, writer);
 184   }
 185
 186   // Flush encoder.
 187   while (encode_frame(&codec, NULL, -1, 1, 0, VPX_DL_GOOD_QUALITY, writer)) {}
 188
 189   printf("\n");
 190
 191   if (vpx_codec_destroy(&codec))
 192     die_codec(&codec, "Failed to destroy codec.");
 193
 194   vpx_video_writer_close(writer);
 195
 196   printf("Pass 1 complete. Processed %d frames.\n", frame_count);
 197 }
 198
 199 int main(int argc, char **argv) {
 200   FILE *infile = NULL;
 201   int w, h;
 202   vpx_codec_ctx_t codec;
 203   vpx_codec_enc_cfg_t cfg;
 204   vpx_image_t raw;
 205   vpx_codec_err_t res;
 206   vpx_fixed_buf_t stats;
 207
 208   const VpxInterface *encoder = NULL;
 209   const int fps = 30;        // TODO(dkovalev) add command line argument
 210   const int bitrate = 200;   // kbit/s TODO(dkovalev) add command line argument
 211   const char *const codec_arg = argv[1];
 212   const char *const width_arg = argv[2];
 213   const char *const height_arg = argv[3];
 214   const char *const infile_arg = argv[4];
 215   const char *const outfile_arg = argv[5];
 216   exec_name = argv[0];
 217
 218   if (argc != 6)
 219     die("Invalid number of arguments.");
 220
 221   encoder = get_vpx_encoder_by_name(codec_arg);
 222   if (!encoder)
 223     die("Unsupported codec.");
 224
 225   w = strtol(width_arg, NULL, 0);
 226   h = strtol(height_arg, NULL, 0);
 227
 228   if (w  <= 0 || h <= 0 || (w % 2) != 0 || (h  % 2) != 0)
 229     die("Invalid frame size: %dx%d", w, h);
 230
 231   if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, w, h, 1))
 232     die("Failed to allocate image", w, h);
 233
 234   printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface()));
 235
 236   // Configuration
 237   res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0);
 238   if (res)
 239     die_codec(&codec, "Failed to get default codec config.");
 240
 241   cfg.g_w = w;
 242   cfg.g_h = h;
 243   cfg.g_timebase.num = 1;
 244   cfg.g_timebase.den = fps;
 245   cfg.rc_target_bitrate = bitrate;
 246
 247   if (!(infile = fopen(infile_arg, "rb")))
 248     die("Failed to open %s for reading", infile_arg);
 249
 250   // Pass 0
 251   cfg.g_pass = VPX_RC_FIRST_PASS;
 252   stats = pass0(&raw, infile, encoder, &cfg);
 253
 254   // Pass 1
 255   rewind(infile);
 256   cfg.g_pass = VPX_RC_LAST_PASS;
 257   cfg.rc_twopass_stats_in = stats;
 258   pass1(&raw, infile, outfile_arg, encoder, &cfg);
 259   free(stats.buf);
 260
 261   vpx_img_free(&raw);
 262   fclose(infile);
 263
 264   return EXIT_SUCCESS;
 265 }