This is an example demonstrating how to control the VP8 encoder’s reference frame selection and update mechanism for video applications that benefit from a scalable bitstream.
Scalable frame patterns are most useful in an error resilient context,
so error resiliency mode is enabled, as in the error_resilient.c
example. In addition, we want to disable automatic keyframe selection,
so we force an interval of 1000 frames.
<br />/* Enable error resilient mode */ cfg.g_error_resilient = 1; cfg.g_lag_in_frames = 0; cfg.kf_mode = VPX_KF_FIXED; /* Disable automatic keyframe placement */ cfg.kf_min_dist = cfg.kf_max_dist = 1000;
This example uses the following frame pattern (L->last_frame, G->golden_frame, A->alt_ref_frame):
Change this variable to test the 3 decodable streams case.
int num_streams = 5;
flags = 0; if(num_streams == 5) { switch(frame_cnt % 16) { case 0: flags |= VPX_EFLAG_FORCE_KF; flags |= VP8_EFLAG_FORCE_GF; flags |= VP8_EFLAG_FORCE_ARF; break; case 1: case 3: case 5: case 7: case 9: case 11: case 13: case 15: flags |= VP8_EFLAG_NO_UPD_LAST; flags |= VP8_EFLAG_NO_UPD_GF; flags |= VP8_EFLAG_NO_UPD_ARF; break; case 2: case 6: case 10: case 14: break; case 4: flags |= VP8_EFLAG_NO_REF_LAST; flags |= VP8_EFLAG_FORCE_GF; break; case 8: flags |= VP8_EFLAG_NO_REF_LAST; flags |= VP8_EFLAG_NO_REF_GF; flags |= VP8_EFLAG_FORCE_GF; flags |= VP8_EFLAG_FORCE_ARF; break; case 12: flags |= VP8_EFLAG_NO_REF_LAST; flags |= VP8_EFLAG_FORCE_GF; break; } } else { switch(frame_cnt % 9) { case 0: if(frame_cnt==0) { flags |= VPX_EFLAG_FORCE_KF; } else { cfg.rc_max_quantizer = 26; cfg.rc_min_quantizer = 0; cfg.rc_target_bitrate = 300; flags |= VP8_EFLAG_NO_REF_LAST; flags |= VP8_EFLAG_NO_REF_ARF; } flags |= VP8_EFLAG_FORCE_GF; flags |= VP8_EFLAG_FORCE_ARF; break; case 1: case 2: case 4: case 5: case 7: case 8: cfg.rc_max_quantizer = 45; cfg.rc_min_quantizer = 0; cfg.rc_target_bitrate = 230; break; case 3: case 6: cfg.rc_max_quantizer = 45; cfg.rc_min_quantizer = 0; cfg.rc_target_bitrate = 215; flags |= VP8_EFLAG_NO_REF_LAST; flags |= VP8_EFLAG_FORCE_ARF; break; } }
Use the decode_with_drops example to decode with various dropped frame
patterns. Good patterns to start with are 1/2, 3/4, 7/8, and 15/16
drops.
/* Copyright (c) 2010 The VP8 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. */ /* This is an example demonstrating how to control the VP8 encoder's reference frame selection and update mechanism for video applications that benefit from a scalable bitstream. */ #include <stdio.h> #include <stdlib.h> #include <stdarg.h> #include <string.h> #define VPX_CODEC_DISABLE_COMPAT 1 #include "vpx/vpx_encoder.h" #include "vpx/vp8cx.h" #define interface (&vpx_codec_vp8_cx_algo) #define fourcc 0x30385056 #define IVF_FILE_HDR_SZ (32) #define IVF_FRAME_HDR_SZ (12) static void mem_put_le16(char *mem, unsigned int val) { mem[0] = val; mem[1] = val>>8; } static void mem_put_le32(char *mem, unsigned int val) { mem[0] = val; mem[1] = val>>8; mem[2] = val>>16; mem[3] = val>>24; } static void die(const char *fmt, ...) { va_list ap; va_start(ap, fmt); vprintf(fmt, ap); if(fmt[strlen(fmt)-1] != '\n') printf("\n"); exit(EXIT_FAILURE); } static void die_codec(vpx_codec_ctx_t *ctx, const char *s) { const char *detail = vpx_codec_error_detail(ctx); printf("%s: %s\n", s, vpx_codec_error(ctx)); if(detail) printf(" %s\n",detail); exit(EXIT_FAILURE); } static int read_frame(FILE *f, vpx_image_t *img) { size_t nbytes, to_read; int res = 1; to_read = img->w*img->h*3/2; nbytes = fread(img->planes[0], 1, to_read, f); if(nbytes != to_read) { res = 0; if(nbytes > 0) printf("Warning: Read partial frame. Check your width & height!\n"); } return res; } static void write_ivf_file_header(FILE *outfile, const vpx_codec_enc_cfg_t *cfg, int frame_cnt) { char header[32]; if(cfg->g_pass != VPX_RC_ONE_PASS && cfg->g_pass != VPX_RC_LAST_PASS) return; header[0] = 'D'; header[1] = 'K'; header[2] = 'I'; header[3] = 'F'; mem_put_le16(header+4, 0); /* version */ mem_put_le16(header+6, 32); /* headersize */ mem_put_le32(header+8, fourcc); /* headersize */ mem_put_le16(header+12, cfg->g_w); /* width */ mem_put_le16(header+14, cfg->g_h); /* height */ mem_put_le32(header+16, cfg->g_timebase.den); /* rate */ mem_put_le32(header+20, cfg->g_timebase.num); /* scale */ mem_put_le32(header+24, frame_cnt); /* length */ mem_put_le32(header+28, 0); /* unused */ fwrite(header, 1, 32, outfile); } static void write_ivf_frame_header(FILE *outfile, const vpx_codec_cx_pkt_t *pkt) { char header[12]; vpx_codec_pts_t pts; if(pkt->kind != VPX_CODEC_CX_FRAME_PKT) return; pts = pkt->data.frame.pts; mem_put_le32(header, pkt->data.frame.sz); mem_put_le32(header+4, pts&0xFFFFFFFF); mem_put_le32(header+8, pts >> 32); fwrite(header, 1, 12, outfile); } int main(int argc, char **argv) { FILE *infile, *outfile; vpx_codec_ctx_t codec; vpx_codec_enc_cfg_t cfg; int frame_cnt = 0; unsigned char file_hdr[IVF_FILE_HDR_SZ]; unsigned char frame_hdr[IVF_FRAME_HDR_SZ]; vpx_image_t raw; vpx_codec_err_t res; long width; long height; int frame_avail; int got_data; int flags = 0; int num_streams = 5; // /* Open files */ if(argc!=5) die("Usage: %s <width> <height> <infile> <outfile>\n", argv[0]); width = strtol(argv[1], NULL, 0); height = strtol(argv[2], NULL, 0); if(width < 16 || width%2 || height <16 || height%2) die("Invalid resolution: %ldx%ld", width, height); if(!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, width, height, 1)) die("Faile to allocate image", width, height); if(!(outfile = fopen(argv[4], "wb"))) die("Failed to open %s for writing", argv[4]); printf("Using %s\n",vpx_codec_iface_name(interface)); /* Populate encoder configuration */ res = vpx_codec_enc_config_default(interface, &cfg, 0); if(res) { printf("Failed to get config: %s\n", vpx_codec_err_to_string(res)); return EXIT_FAILURE; } /* Update the default configuration with our settings */ cfg.rc_target_bitrate = width * height * cfg.rc_target_bitrate / cfg.g_w / cfg.g_h; cfg.g_w = width; cfg.g_h = height; // /* Enable error resilient mode */ // cfg.g_error_resilient = 1; // cfg.g_lag_in_frames = 0; // cfg.kf_mode = VPX_KF_FIXED; // // /* Disable automatic keyframe placement */ // cfg.kf_min_dist = cfg.kf_max_dist = 1000; // write_ivf_file_header(outfile, &cfg, 0); /* Open input file for this encoding pass */ if(!(infile = fopen(argv[3], "rb"))) die("Failed to open %s for reading", argv[3]); /* Initialize codec */ if(vpx_codec_enc_init(&codec, interface, &cfg, 0)) die_codec(&codec, "Failed to initialize encoder"); frame_avail = 1; got_data = 0; while(frame_avail || got_data) { vpx_codec_iter_t iter = NULL; const vpx_codec_cx_pkt_t *pkt; flags = 0; // if(num_streams == 5) // { // switch(frame_cnt % 16) { // case 0: // flags |= VPX_EFLAG_FORCE_KF; // flags |= VP8_EFLAG_FORCE_GF; // flags |= VP8_EFLAG_FORCE_ARF; // break; // case 1: // case 3: // case 5: // case 7: // case 9: // case 11: // case 13: // case 15: // flags |= VP8_EFLAG_NO_UPD_LAST; // flags |= VP8_EFLAG_NO_UPD_GF; // flags |= VP8_EFLAG_NO_UPD_ARF; // break; // case 2: // case 6: // case 10: // case 14: // break; // case 4: // flags |= VP8_EFLAG_NO_REF_LAST; // flags |= VP8_EFLAG_FORCE_GF; // break; // case 8: // flags |= VP8_EFLAG_NO_REF_LAST; // flags |= VP8_EFLAG_NO_REF_GF; // flags |= VP8_EFLAG_FORCE_GF; // flags |= VP8_EFLAG_FORCE_ARF; // break; // case 12: // flags |= VP8_EFLAG_NO_REF_LAST; // flags |= VP8_EFLAG_FORCE_GF; // break; // } // } // else // { // switch(frame_cnt % 9) { // case 0: // if(frame_cnt==0) // { // flags |= VPX_EFLAG_FORCE_KF; // } // else // { // cfg.rc_max_quantizer = 26; // cfg.rc_min_quantizer = 0; // cfg.rc_target_bitrate = 300; // flags |= VP8_EFLAG_NO_REF_LAST; // flags |= VP8_EFLAG_NO_REF_ARF; // } // flags |= VP8_EFLAG_FORCE_GF; // flags |= VP8_EFLAG_FORCE_ARF; // break; // case 1: // case 2: // case 4: // case 5: // case 7: // case 8: // cfg.rc_max_quantizer = 45; // cfg.rc_min_quantizer = 0; // cfg.rc_target_bitrate = 230; // break; // case 3: // case 6: // cfg.rc_max_quantizer = 45; // cfg.rc_min_quantizer = 0; // cfg.rc_target_bitrate = 215; // flags |= VP8_EFLAG_NO_REF_LAST; // flags |= VP8_EFLAG_FORCE_ARF; // break; // } // } // frame_avail = read_frame(infile, &raw); if(vpx_codec_encode(&codec, frame_avail? &raw : NULL, frame_cnt, 1, flags, VPX_DL_REALTIME)) die_codec(&codec, "Failed to encode frame"); got_data = 0; while( (pkt = vpx_codec_get_cx_data(&codec, &iter)) ) { got_data = 1; switch(pkt->kind) { case VPX_CODEC_CX_FRAME_PKT: write_ivf_frame_header(outfile, pkt); fwrite(pkt->data.frame.buf, 1, pkt->data.frame.sz, outfile); break; default: break; } printf(pkt->kind == VPX_CODEC_CX_FRAME_PKT && (pkt->data.frame.flags & VPX_FRAME_IS_KEY)? "K":"."); fflush(stdout); } frame_cnt++; } printf("\n"); fclose(infile); printf("Processed %d frames.\n",frame_cnt-1); if(vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec"); /* Try to rewrite the file header with the actual frame count */ if(!fseek(outfile, 0, SEEK_SET)) write_ivf_file_header(outfile, &cfg, frame_cnt-1); fclose(outfile); return EXIT_SUCCESS; }
1.6.3