1/* 2 * Copyright (c) 2010 Stefano Sabatini 3 * 4 * This file is part of Libav. 5 * 6 * Libav is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * Libav is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with Libav; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21/** 22 * @file 23 * Set timebase for the output link. 24 */ 25 26#include "libavutil/avstring.h" 27#include "libavutil/eval.h" 28#include "libavutil/mathematics.h" 29#include "libavutil/rational.h" 30#include "avfilter.h" 31#include "internal.h" 32 33static const char *var_names[] = { 34 "E", 35 "PHI", 36 "PI", 37 "AVTB", /* default timebase 1/AV_TIME_BASE */ 38 "intb", /* input timebase */ 39 NULL 40}; 41 42enum var_name { 43 VAR_E, 44 VAR_PHI, 45 VAR_PI, 46 VAR_AVTB, 47 VAR_INTB, 48 VAR_VARS_NB 49}; 50 51typedef struct { 52 char tb_expr[256]; 53 double var_values[VAR_VARS_NB]; 54} SetTBContext; 55 56static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) 57{ 58 SetTBContext *settb = ctx->priv; 59 av_strlcpy(settb->tb_expr, "intb", sizeof(settb->tb_expr)); 60 61 if (args) 62 sscanf(args, "%255[^:]", settb->tb_expr); 63 64 return 0; 65} 66 67static int config_output_props(AVFilterLink *outlink) 68{ 69 AVFilterContext *ctx = outlink->src; 70 SetTBContext *settb = ctx->priv; 71 AVFilterLink *inlink = ctx->inputs[0]; 72 AVRational time_base; 73 int ret; 74 double res; 75 76 settb->var_values[VAR_E] = M_E; 77 settb->var_values[VAR_PHI] = M_PHI; 78 settb->var_values[VAR_PI] = M_PI; 79 settb->var_values[VAR_AVTB] = av_q2d(AV_TIME_BASE_Q); 80 settb->var_values[VAR_INTB] = av_q2d(inlink->time_base); 81 82 outlink->w = inlink->w; 83 outlink->h = inlink->h; 84 85 if ((ret = av_expr_parse_and_eval(&res, settb->tb_expr, var_names, settb->var_values, 86 NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) { 87 av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr); 88 return ret; 89 } 90 time_base = av_d2q(res, INT_MAX); 91 if (time_base.num <= 0 || time_base.den <= 0) { 92 av_log(ctx, AV_LOG_ERROR, 93 "Invalid non-positive values for the timebase num:%d or den:%d.\n", 94 time_base.num, time_base.den); 95 return AVERROR(EINVAL); 96 } 97 98 outlink->time_base = time_base; 99 av_log(outlink->src, AV_LOG_INFO, "tb:%d/%d -> tb:%d/%d\n", 100 inlink ->time_base.num, inlink ->time_base.den, 101 outlink->time_base.num, outlink->time_base.den); 102 103 return 0; 104} 105 106static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref) 107{ 108 AVFilterContext *ctx = inlink->dst; 109 AVFilterLink *outlink = ctx->outputs[0]; 110 AVFilterBufferRef *picref2 = picref; 111 112 if (av_cmp_q(inlink->time_base, outlink->time_base)) { 113 picref2 = avfilter_ref_buffer(picref, ~0); 114 picref2->pts = av_rescale_q(picref->pts, inlink->time_base, outlink->time_base); 115 av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n", 116 inlink ->time_base.num, inlink ->time_base.den, picref ->pts, 117 outlink->time_base.num, outlink->time_base.den, picref2->pts); 118 avfilter_unref_buffer(picref); 119 } 120 121 avfilter_start_frame(outlink, picref2); 122} 123 124AVFilter avfilter_vf_settb = { 125 .name = "settb", 126 .description = NULL_IF_CONFIG_SMALL("Set timebase for the output link."), 127 .init = init, 128 129 .priv_size = sizeof(SetTBContext), 130 131 .inputs = (AVFilterPad[]) {{ .name = "default", 132 .type = AVMEDIA_TYPE_VIDEO, 133 .get_video_buffer = avfilter_null_get_video_buffer, 134 .start_frame = start_frame, 135 .end_frame = avfilter_null_end_frame }, 136 { .name = NULL }}, 137 138 .outputs = (AVFilterPad[]) {{ .name = "default", 139 .type = AVMEDIA_TYPE_VIDEO, 140 .config_props = config_output_props, }, 141 { .name = NULL}}, 142}; 143