mirror of https://github.com/FFmpeg/FFmpeg.git
Factorize code, extend the functionality of the filter, and make it return empty buffers. This is useful for filters which ignore the input frames content. This is also changing the syntax of the nullsrc source, and dropping the framerate expression evaluation, which does not look particularly useful.pull/2/head
Stefano Sabatini
13 years ago
parent
3092509b08
commit
1f4652068e
5 changed files with 56 additions and 142 deletions
@ -1,121 +0,0 @@ |
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/*
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/**
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* @file |
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* null video source |
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*/ |
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#include "libavutil/avstring.h" |
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#include "libavutil/eval.h" |
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#include "libavutil/mathematics.h" |
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#include "libavutil/parseutils.h" |
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#include "avfilter.h" |
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static const char *var_names[] = { |
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"AVTB", /* default timebase 1/AV_TIME_BASE */ |
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NULL |
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}; |
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enum var_name { |
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VAR_AVTB, |
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VAR_VARS_NB |
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}; |
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typedef struct { |
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int w, h; |
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char tb_expr[256]; |
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double var_values[VAR_VARS_NB]; |
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} NullContext; |
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static int init(AVFilterContext *ctx, const char *args, void *opaque) |
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{ |
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NullContext *priv = ctx->priv; |
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priv->w = 352; |
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priv->h = 288; |
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av_strlcpy(priv->tb_expr, "AVTB", sizeof(priv->tb_expr)); |
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if (args) |
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sscanf(args, "%d:%d:%255[^:]", &priv->w, &priv->h, priv->tb_expr); |
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if (priv->w <= 0 || priv->h <= 0) { |
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av_log(ctx, AV_LOG_ERROR, "Non-positive size values are not acceptable.\n"); |
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return AVERROR(EINVAL); |
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} |
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return 0; |
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} |
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static int config_props(AVFilterLink *outlink) |
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{ |
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AVFilterContext *ctx = outlink->src; |
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NullContext *priv = ctx->priv; |
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AVRational tb; |
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int ret; |
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double res; |
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priv->var_values[VAR_AVTB] = av_q2d(AV_TIME_BASE_Q); |
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if ((ret = av_expr_parse_and_eval(&res, priv->tb_expr, var_names, priv->var_values, |
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NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) { |
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av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", priv->tb_expr); |
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return ret; |
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} |
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tb = av_d2q(res, INT_MAX); |
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if (tb.num <= 0 || tb.den <= 0) { |
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av_log(ctx, AV_LOG_ERROR, |
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"Invalid non-positive value for the timebase %d/%d.\n", |
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tb.num, tb.den); |
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return AVERROR(EINVAL); |
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} |
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outlink->w = priv->w; |
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outlink->h = priv->h; |
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outlink->time_base = tb; |
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av_log(outlink->src, AV_LOG_INFO, "w:%d h:%d tb:%d/%d\n", priv->w, priv->h, |
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tb.num, tb.den); |
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return 0; |
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} |
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static int request_frame(AVFilterLink *link) |
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{ |
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return -1; |
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} |
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AVFilter avfilter_vsrc_nullsrc = { |
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.name = "nullsrc", |
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.description = NULL_IF_CONFIG_SMALL("Null video source, never return images."), |
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.init = init, |
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.priv_size = sizeof(NullContext), |
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.inputs = (AVFilterPad[]) {{ .name = NULL}}, |
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.outputs = (AVFilterPad[]) { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_VIDEO, |
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.config_props = config_props, |
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.request_frame = request_frame, |
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}, |
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{ .name = NULL} |
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}, |
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}; |
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