yading@10: /*
yading@10:  * Copyright 2007 Bobby Bingham
yading@10:  * Copyright 2012 Robert Nagy <ronag89 gmail com>
yading@10:  * Copyright 2012 Anton Khirnov <anton khirnov net>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * a filter enforcing given constant framerate
yading@10:  */
yading@10: 
yading@10: #include "libavutil/common.h"
yading@10: #include "libavutil/fifo.h"
yading@10: #include "libavutil/mathematics.h"
yading@10: #include "libavutil/opt.h"
yading@10: #include "libavutil/parseutils.h"
yading@10: 
yading@10: #include "avfilter.h"
yading@10: #include "internal.h"
yading@10: #include "video.h"
yading@10: 
yading@10: typedef struct FPSContext {
yading@10:     const AVClass *class;
yading@10: 
yading@10:     AVFifoBuffer *fifo;     ///< store frames until we get two successive timestamps
yading@10: 
yading@10:     /* timestamps in input timebase */
yading@10:     int64_t first_pts;      ///< pts of the first frame that arrived on this filter
yading@10:     int64_t pts;            ///< pts of the first frame currently in the fifo
yading@10: 
yading@10:     AVRational framerate;   ///< target framerate
yading@10:     int rounding;           ///< AVRounding method for timestamps
yading@10: 
yading@10:     /* statistics */
yading@10:     int frames_in;             ///< number of frames on input
yading@10:     int frames_out;            ///< number of frames on output
yading@10:     int dup;                   ///< number of frames duplicated
yading@10:     int drop;                  ///< number of framed dropped
yading@10: } FPSContext;
yading@10: 
yading@10: #define OFFSET(x) offsetof(FPSContext, x)
yading@10: #define V AV_OPT_FLAG_VIDEO_PARAM
yading@10: #define F AV_OPT_FLAG_FILTERING_PARAM
yading@10: static const AVOption fps_options[] = {
yading@10:     { "fps", "A string describing desired output framerate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, { .str = "25" }, .flags = V|F },
yading@10:     { "round", "set rounding method for timestamps", OFFSET(rounding), AV_OPT_TYPE_INT, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
yading@10:     { "zero", "round towards 0",      OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_ZERO     }, 0, 5, V|F, "round" },
yading@10:     { "inf",  "round away from 0",    OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_INF      }, 0, 5, V|F, "round" },
yading@10:     { "down", "round towards -infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_DOWN     }, 0, 5, V|F, "round" },
yading@10:     { "up",   "round towards +infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_UP       }, 0, 5, V|F, "round" },
yading@10:     { "near", "round to nearest",     OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
yading@10:     { NULL },
yading@10: };
yading@10: 
yading@10: AVFILTER_DEFINE_CLASS(fps);
yading@10: 
yading@10: static av_cold int init(AVFilterContext *ctx)
yading@10: {
yading@10:     FPSContext *s = ctx->priv;
yading@10: 
yading@10:     if (!(s->fifo = av_fifo_alloc(2*sizeof(AVFrame*))))
yading@10:         return AVERROR(ENOMEM);
yading@10: 
yading@10:     av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static void flush_fifo(AVFifoBuffer *fifo)
yading@10: {
yading@10:     while (av_fifo_size(fifo)) {
yading@10:         AVFrame *tmp;
yading@10:         av_fifo_generic_read(fifo, &tmp, sizeof(tmp), NULL);
yading@10:         av_frame_free(&tmp);
yading@10:     }
yading@10: }
yading@10: 
yading@10: static av_cold void uninit(AVFilterContext *ctx)
yading@10: {
yading@10:     FPSContext *s = ctx->priv;
yading@10:     if (s->fifo) {
yading@10:         s->drop += av_fifo_size(s->fifo) / sizeof(AVFrame*);
yading@10:         flush_fifo(s->fifo);
yading@10:         av_fifo_free(s->fifo);
yading@10:     }
yading@10: 
yading@10:     av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, "
yading@10:            "%d frames duplicated.\n", s->frames_in, s->frames_out, s->drop, s->dup);
yading@10: }
yading@10: 
yading@10: static int config_props(AVFilterLink* link)
yading@10: {
yading@10:     FPSContext   *s = link->src->priv;
yading@10: 
yading@10:     link->time_base = av_inv_q(s->framerate);
yading@10:     link->frame_rate= s->framerate;
yading@10:     link->w         = link->src->inputs[0]->w;
yading@10:     link->h         = link->src->inputs[0]->h;
yading@10:     s->pts          = AV_NOPTS_VALUE;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int request_frame(AVFilterLink *outlink)
yading@10: {
yading@10:     AVFilterContext *ctx = outlink->src;
yading@10:     FPSContext        *s = ctx->priv;
yading@10:     int frames_out = s->frames_out;
yading@10:     int ret = 0;
yading@10: 
yading@10:     while (ret >= 0 && s->frames_out == frames_out)
yading@10:         ret = ff_request_frame(ctx->inputs[0]);
yading@10: 
yading@10:     /* flush the fifo */
yading@10:     if (ret == AVERROR_EOF && av_fifo_size(s->fifo)) {
yading@10:         int i;
yading@10:         for (i = 0; av_fifo_size(s->fifo); i++) {
yading@10:             AVFrame *buf;
yading@10: 
yading@10:             av_fifo_generic_read(s->fifo, &buf, sizeof(buf), NULL);
yading@10:             buf->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base,
yading@10:                                     outlink->time_base) + s->frames_out;
yading@10: 
yading@10:             if ((ret = ff_filter_frame(outlink, buf)) < 0)
yading@10:                 return ret;
yading@10: 
yading@10:             s->frames_out++;
yading@10:         }
yading@10:         return 0;
yading@10:     }
yading@10: 
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: static int write_to_fifo(AVFifoBuffer *fifo, AVFrame *buf)
yading@10: {
yading@10:     int ret;
yading@10: 
yading@10:     if (!av_fifo_space(fifo) &&
yading@10:         (ret = av_fifo_realloc2(fifo, 2*av_fifo_size(fifo)))) {
yading@10:         av_frame_free(&buf);
yading@10:         return ret;
yading@10:     }
yading@10: 
yading@10:     av_fifo_generic_write(fifo, &buf, sizeof(buf), NULL);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
yading@10: {
yading@10:     AVFilterContext    *ctx = inlink->dst;
yading@10:     FPSContext           *s = ctx->priv;
yading@10:     AVFilterLink   *outlink = ctx->outputs[0];
yading@10:     int64_t delta;
yading@10:     int i, ret;
yading@10: 
yading@10:     s->frames_in++;
yading@10:     /* discard frames until we get the first timestamp */
yading@10:     if (s->pts == AV_NOPTS_VALUE) {
yading@10:         if (buf->pts != AV_NOPTS_VALUE) {
yading@10:             ret = write_to_fifo(s->fifo, buf);
yading@10:             if (ret < 0)
yading@10:                 return ret;
yading@10: 
yading@10:             s->first_pts = s->pts = buf->pts;
yading@10:         } else {
yading@10:             av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no "
yading@10:                    "timestamp.\n");
yading@10:             av_frame_free(&buf);
yading@10:             s->drop++;
yading@10:         }
yading@10:         return 0;
yading@10:     }
yading@10: 
yading@10:     /* now wait for the next timestamp */
yading@10:     if (buf->pts == AV_NOPTS_VALUE) {
yading@10:         return write_to_fifo(s->fifo, buf);
yading@10:     }
yading@10: 
yading@10:     /* number of output frames */
yading@10:     delta = av_rescale_q_rnd(buf->pts - s->pts, inlink->time_base,
yading@10:                              outlink->time_base, s->rounding);
yading@10: 
yading@10:     if (delta < 1) {
yading@10:         /* drop the frame and everything buffered except the first */
yading@10:         AVFrame *tmp;
yading@10:         int drop = av_fifo_size(s->fifo)/sizeof(AVFrame*);
yading@10: 
yading@10:         av_log(ctx, AV_LOG_DEBUG, "Dropping %d frame(s).\n", drop);
yading@10:         s->drop += drop;
yading@10: 
yading@10:         av_fifo_generic_read(s->fifo, &tmp, sizeof(tmp), NULL);
yading@10:         flush_fifo(s->fifo);
yading@10:         ret = write_to_fifo(s->fifo, tmp);
yading@10: 
yading@10:         av_frame_free(&buf);
yading@10:         return ret;
yading@10:     }
yading@10: 
yading@10:     /* can output >= 1 frames */
yading@10:     for (i = 0; i < delta; i++) {
yading@10:         AVFrame *buf_out;
yading@10:         av_fifo_generic_read(s->fifo, &buf_out, sizeof(buf_out), NULL);
yading@10: 
yading@10:         /* duplicate the frame if needed */
yading@10:         if (!av_fifo_size(s->fifo) && i < delta - 1) {
yading@10:             AVFrame *dup = av_frame_clone(buf_out);
yading@10: 
yading@10:             av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n");
yading@10:             if (dup)
yading@10:                 ret = write_to_fifo(s->fifo, dup);
yading@10:             else
yading@10:                 ret = AVERROR(ENOMEM);
yading@10: 
yading@10:             if (ret < 0) {
yading@10:                 av_frame_free(&buf_out);
yading@10:                 av_frame_free(&buf);
yading@10:                 return ret;
yading@10:             }
yading@10: 
yading@10:             s->dup++;
yading@10:         }
yading@10: 
yading@10:         buf_out->pts = av_rescale_q(s->first_pts, inlink->time_base,
yading@10:                                     outlink->time_base) + s->frames_out;
yading@10: 
yading@10:         if ((ret = ff_filter_frame(outlink, buf_out)) < 0) {
yading@10:             av_frame_free(&buf);
yading@10:             return ret;
yading@10:         }
yading@10: 
yading@10:         s->frames_out++;
yading@10:     }
yading@10:     flush_fifo(s->fifo);
yading@10: 
yading@10:     ret = write_to_fifo(s->fifo, buf);
yading@10:     s->pts = s->first_pts + av_rescale_q(s->frames_out, outlink->time_base, inlink->time_base);
yading@10: 
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_fps_inputs[] = {
yading@10:     {
yading@10:         .name        = "default",
yading@10:         .type        = AVMEDIA_TYPE_VIDEO,
yading@10:         .filter_frame = filter_frame,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_fps_outputs[] = {
yading@10:     {
yading@10:         .name          = "default",
yading@10:         .type          = AVMEDIA_TYPE_VIDEO,
yading@10:         .request_frame = request_frame,
yading@10:         .config_props  = config_props
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFilter avfilter_vf_fps = {
yading@10:     .name        = "fps",
yading@10:     .description = NULL_IF_CONFIG_SMALL("Force constant framerate."),
yading@10: 
yading@10:     .init      = init,
yading@10:     .uninit    = uninit,
yading@10: 
yading@10:     .priv_size = sizeof(FPSContext),
yading@10:     .priv_class = &fps_class,
yading@10: 
yading@10:     .inputs    = avfilter_vf_fps_inputs,
yading@10:     .outputs   = avfilter_vf_fps_outputs,
yading@10: };