ref: b2120948391f8beb7ff74bd46b83da1ff2020f49
dir: /examples/twopass_encoder.c/
/* * Copyright (c) 2010 The WebM project authors. All Rights Reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ // Two Pass Encoder // ================ // // This is an example of a two pass encoder loop. It takes an input file in // YV12 format, passes it through the encoder twice, and writes the compressed // frames to disk in IVF format. It builds upon the simple_encoder example. // // Twopass Variables // ----------------- // Twopass mode needs to track the current pass number and the buffer of // statistics packets. // // Updating The Configuration // --------------------------------- // In two pass mode, the configuration has to be updated on each pass. The // statistics buffer is passed on the last pass. // // Encoding A Frame // ---------------- // Encoding a frame in two pass mode is identical to the simple encoder // example. To increase the quality while sacrificing encoding speed, // VPX_DL_BEST_QUALITY can be used in place of VPX_DL_GOOD_QUALITY. // // Processing Statistics Packets // ----------------------------- // Each packet of type `VPX_CODEC_CX_FRAME_PKT` contains the encoded data // for this frame. We write a IVF frame header, followed by the raw data. // // // Pass Progress Reporting // ----------------------------- // It's sometimes helpful to see when each pass completes. // // // Clean-up // ----------------------------- // Destruction of the encoder instance must be done on each pass. The // raw image should be destroyed at the end as usual. #include <stdio.h> #include <stdlib.h> #include <string.h> #include "vpx/vpx_encoder.h" #include "../tools_common.h" #include "../video_writer.h" static const char *exec_name; void usage_exit(void) { fprintf(stderr, "Usage: %s <codec> <width> <height> <infile> <outfile>\n", exec_name); exit(EXIT_FAILURE); } static int get_frame_stats(vpx_codec_ctx_t *ctx, const vpx_image_t *img, vpx_codec_pts_t pts, unsigned int duration, vpx_enc_frame_flags_t flags, unsigned int deadline, vpx_fixed_buf_t *stats) { int got_pkts = 0; vpx_codec_iter_t iter = NULL; const vpx_codec_cx_pkt_t *pkt = NULL; const vpx_codec_err_t res = vpx_codec_encode(ctx, img, pts, duration, flags, deadline); if (res != VPX_CODEC_OK) die_codec(ctx, "Failed to get frame stats."); while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) { got_pkts = 1; if (pkt->kind == VPX_CODEC_STATS_PKT) { const uint8_t *const pkt_buf = pkt->data.twopass_stats.buf; const size_t pkt_size = pkt->data.twopass_stats.sz; stats->buf = realloc(stats->buf, stats->sz + pkt_size); memcpy((uint8_t *)stats->buf + stats->sz, pkt_buf, pkt_size); stats->sz += pkt_size; } } return got_pkts; } static int encode_frame(vpx_codec_ctx_t *ctx, const vpx_image_t *img, vpx_codec_pts_t pts, unsigned int duration, vpx_enc_frame_flags_t flags, unsigned int deadline, VpxVideoWriter *writer) { int got_pkts = 0; vpx_codec_iter_t iter = NULL; const vpx_codec_cx_pkt_t *pkt = NULL; const vpx_codec_err_t res = vpx_codec_encode(ctx, img, pts, duration, flags, deadline); if (res != VPX_CODEC_OK) die_codec(ctx, "Failed to encode frame."); while ((pkt = vpx_codec_get_cx_data(ctx, &iter)) != NULL) { got_pkts = 1; if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) { const int keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0; if (!vpx_video_writer_write_frame(writer, pkt->data.frame.buf, pkt->data.frame.sz, pkt->data.frame.pts)) die_codec(ctx, "Failed to write compressed frame."); printf(keyframe ? "K" : "."); fflush(stdout); } } return got_pkts; } static vpx_fixed_buf_t pass0(vpx_image_t *raw, FILE *infile, const VpxInterface *encoder, const vpx_codec_enc_cfg_t *cfg) { vpx_codec_ctx_t codec; int frame_count = 0; vpx_fixed_buf_t stats = {NULL, 0}; if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0)) die_codec(&codec, "Failed to initialize encoder"); // Calculate frame statistics. while (vpx_img_read(raw, infile)) { ++frame_count; get_frame_stats(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY, &stats); } // Flush encoder. while (get_frame_stats(&codec, NULL, frame_count, 1, 0, VPX_DL_GOOD_QUALITY, &stats)) {} printf("Pass 0 complete. Processed %d frames.\n", frame_count); if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec."); return stats; } static void pass1(vpx_image_t *raw, FILE *infile, const char *outfile_name, const VpxInterface *encoder, const vpx_codec_enc_cfg_t *cfg) { VpxVideoInfo info = { encoder->fourcc, cfg->g_w, cfg->g_h, {cfg->g_timebase.num, cfg->g_timebase.den} }; VpxVideoWriter *writer = NULL; vpx_codec_ctx_t codec; int frame_count = 0; writer = vpx_video_writer_open(outfile_name, kContainerIVF, &info); if (!writer) die("Failed to open %s for writing", outfile_name); if (vpx_codec_enc_init(&codec, encoder->codec_interface(), cfg, 0)) die_codec(&codec, "Failed to initialize encoder"); // Encode frames. while (vpx_img_read(raw, infile)) { ++frame_count; encode_frame(&codec, raw, frame_count, 1, 0, VPX_DL_GOOD_QUALITY, writer); } // Flush encoder. while (encode_frame(&codec, NULL, -1, 1, 0, VPX_DL_GOOD_QUALITY, writer)) {} printf("\n"); if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec."); vpx_video_writer_close(writer); printf("Pass 1 complete. Processed %d frames.\n", frame_count); } int main(int argc, char **argv) { FILE *infile = NULL; int w, h; vpx_codec_ctx_t codec; vpx_codec_enc_cfg_t cfg; vpx_image_t raw; vpx_codec_err_t res; vpx_fixed_buf_t stats; const VpxInterface *encoder = NULL; const int fps = 30; // TODO(dkovalev) add command line argument const int bitrate = 200; // kbit/s TODO(dkovalev) add command line argument const char *const codec_arg = argv[1]; const char *const width_arg = argv[2]; const char *const height_arg = argv[3]; const char *const infile_arg = argv[4]; const char *const outfile_arg = argv[5]; exec_name = argv[0]; if (argc != 6) die("Invalid number of arguments."); encoder = get_vpx_encoder_by_name(codec_arg); if (!encoder) die("Unsupported codec."); w = strtol(width_arg, NULL, 0); h = strtol(height_arg, NULL, 0); if (w <= 0 || h <= 0 || (w % 2) != 0 || (h % 2) != 0) die("Invalid frame size: %dx%d", w, h); if (!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, w, h, 1)) die("Failed to allocate image", w, h); printf("Using %s\n", vpx_codec_iface_name(encoder->codec_interface())); // Configuration res = vpx_codec_enc_config_default(encoder->codec_interface(), &cfg, 0); if (res) die_codec(&codec, "Failed to get default codec config."); cfg.g_w = w; cfg.g_h = h; cfg.g_timebase.num = 1; cfg.g_timebase.den = fps; cfg.rc_target_bitrate = bitrate; if (!(infile = fopen(infile_arg, "rb"))) die("Failed to open %s for reading", infile_arg); // Pass 0 cfg.g_pass = VPX_RC_FIRST_PASS; stats = pass0(&raw, infile, encoder, &cfg); // Pass 1 rewind(infile); cfg.g_pass = VPX_RC_LAST_PASS; cfg.rc_twopass_stats_in = stats; pass1(&raw, infile, outfile_arg, encoder, &cfg); free(stats.buf); vpx_img_free(&raw); fclose(infile); return EXIT_SUCCESS; }