mirror of https://github.com/FFmpeg/FFmpeg.git
Anton Khirnov
13 years ago
parent
7b3b24a8ee
commit
54c5dd89e3
6 changed files with 288 additions and 1 deletions
@ -0,0 +1,271 @@ |
||||
/*
|
||||
* This file is part of Libav. |
||||
* |
||||
* Libav is free software; you can redistribute it and/or |
||||
* modify it under the terms of the GNU Lesser General Public |
||||
* License as published by the Free Software Foundation; either |
||||
* version 2.1 of the License, or (at your option) any later version. |
||||
* |
||||
* Libav is distributed in the hope that it will be useful, |
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
||||
* Lesser General Public License for more details. |
||||
* |
||||
* You should have received a copy of the GNU Lesser General Public |
||||
* License along with Libav; if not, write to the Free Software |
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
||||
*/ |
||||
|
||||
/**
|
||||
* @file |
||||
* a filter enforcing given constant framerate |
||||
*/ |
||||
|
||||
#include "libavutil/fifo.h" |
||||
#include "libavutil/mathematics.h" |
||||
#include "libavutil/opt.h" |
||||
#include "libavutil/parseutils.h" |
||||
|
||||
#include "avfilter.h" |
||||
|
||||
typedef struct FPSContext { |
||||
const AVClass *class; |
||||
|
||||
AVFifoBuffer *fifo; ///< store frames until we get two successive timestamps
|
||||
|
||||
/* timestamps in input timebase */ |
||||
int64_t first_pts; ///< pts of the first frame that arrived on this filter
|
||||
int64_t pts; ///< pts of the first frame currently in the fifo
|
||||
|
||||
AVRational framerate; ///< target framerate
|
||||
char *fps; ///< a string describing target framerate
|
||||
|
||||
/* statistics */ |
||||
int frames_in; ///< number of frames on input
|
||||
int frames_out; ///< number of frames on output
|
||||
int dup; ///< number of frames duplicated
|
||||
int drop; ///< number of framed dropped
|
||||
} FPSContext; |
||||
|
||||
#define OFFSET(x) offsetof(FPSContext, x) |
||||
#define V AV_OPT_FLAG_VIDEO_PARAM |
||||
static const AVOption options[] = { |
||||
{ "fps", "A string describing desired output framerate", OFFSET(fps), AV_OPT_TYPE_STRING, { .str = "25" }, .flags = V }, |
||||
{ NULL }, |
||||
}; |
||||
|
||||
static const AVClass class = { |
||||
.class_name = "FPS filter", |
||||
.item_name = av_default_item_name, |
||||
.option = options, |
||||
.version = LIBAVUTIL_VERSION_INT, |
||||
}; |
||||
|
||||
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) |
||||
{ |
||||
FPSContext *s = ctx->priv; |
||||
int ret; |
||||
|
||||
s->class = &class; |
||||
av_opt_set_defaults(s); |
||||
|
||||
if ((ret = av_set_options_string(s, args, "=", ":")) < 0) { |
||||
av_log(ctx, AV_LOG_ERROR, "Error parsing the options string %s.\n", |
||||
args); |
||||
return ret; |
||||
} |
||||
|
||||
if ((ret = av_parse_video_rate(&s->framerate, s->fps)) < 0) { |
||||
av_log(ctx, AV_LOG_ERROR, "Error parsing framerate %s.\n", s->fps); |
||||
return ret; |
||||
} |
||||
av_opt_free(s); |
||||
|
||||
if (!(s->fifo = av_fifo_alloc(2*sizeof(AVFilterBufferRef*)))) |
||||
return AVERROR(ENOMEM); |
||||
|
||||
av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den); |
||||
return 0; |
||||
} |
||||
|
||||
static void flush_fifo(AVFifoBuffer *fifo) |
||||
{ |
||||
while (av_fifo_size(fifo)) { |
||||
AVFilterBufferRef *tmp; |
||||
av_fifo_generic_read(fifo, &tmp, sizeof(tmp), NULL); |
||||
avfilter_unref_buffer(tmp); |
||||
} |
||||
} |
||||
|
||||
static av_cold void uninit(AVFilterContext *ctx) |
||||
{ |
||||
FPSContext *s = ctx->priv; |
||||
if (s->fifo) { |
||||
flush_fifo(s->fifo); |
||||
av_fifo_free(s->fifo); |
||||
} |
||||
|
||||
av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, " |
||||
"%d frames duplicated.\n", s->frames_in, s->frames_out, s->drop, s->dup); |
||||
} |
||||
|
||||
static int config_props(AVFilterLink* link) |
||||
{ |
||||
FPSContext *s = link->src->priv; |
||||
|
||||
link->time_base = (AVRational){ s->framerate.den, s->framerate.num }; |
||||
link->w = link->src->inputs[0]->w; |
||||
link->h = link->src->inputs[0]->h; |
||||
s->pts = AV_NOPTS_VALUE; |
||||
|
||||
return 0; |
||||
} |
||||
|
||||
static int request_frame(AVFilterLink *outlink) |
||||
{ |
||||
AVFilterContext *ctx = outlink->src; |
||||
FPSContext *s = ctx->priv; |
||||
int frames_out = s->frames_out; |
||||
int ret = 0; |
||||
|
||||
while (ret >= 0 && s->frames_out == frames_out) |
||||
ret = avfilter_request_frame(ctx->inputs[0]); |
||||
|
||||
/* flush the fifo */ |
||||
if (ret == AVERROR_EOF && av_fifo_size(s->fifo)) { |
||||
int i; |
||||
for (i = 0; av_fifo_size(s->fifo); i++) { |
||||
AVFilterBufferRef *buf; |
||||
|
||||
av_fifo_generic_read(s->fifo, &buf, sizeof(buf), NULL); |
||||
buf->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base, |
||||
outlink->time_base) + s->frames_out; |
||||
|
||||
avfilter_start_frame(outlink, buf); |
||||
avfilter_draw_slice(outlink, 0, outlink->h, 1); |
||||
avfilter_end_frame(outlink); |
||||
s->frames_out++; |
||||
} |
||||
return 0; |
||||
} |
||||
|
||||
return ret; |
||||
} |
||||
|
||||
static int write_to_fifo(AVFifoBuffer *fifo, AVFilterBufferRef *buf) |
||||
{ |
||||
int ret; |
||||
|
||||
if (!av_fifo_space(fifo) && |
||||
(ret = av_fifo_realloc2(fifo, 2*av_fifo_size(fifo)))) |
||||
return ret; |
||||
|
||||
av_fifo_generic_write(fifo, &buf, sizeof(buf), NULL); |
||||
return 0; |
||||
} |
||||
|
||||
static void end_frame(AVFilterLink *inlink) |
||||
{ |
||||
AVFilterContext *ctx = inlink->dst; |
||||
FPSContext *s = ctx->priv; |
||||
AVFilterLink *outlink = ctx->outputs[0]; |
||||
AVFilterBufferRef *buf = inlink->cur_buf; |
||||
int64_t delta; |
||||
int i; |
||||
|
||||
s->frames_in++; |
||||
/* discard frames until we get the first timestamp */ |
||||
if (s->pts == AV_NOPTS_VALUE) { |
||||
if (buf->pts != AV_NOPTS_VALUE) { |
||||
write_to_fifo(s->fifo, buf); |
||||
s->first_pts = s->pts = buf->pts; |
||||
} else { |
||||
av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no " |
||||
"timestamp.\n"); |
||||
avfilter_unref_buffer(buf); |
||||
s->drop++; |
||||
} |
||||
return; |
||||
} |
||||
|
||||
/* now wait for the next timestamp */ |
||||
if (buf->pts == AV_NOPTS_VALUE) { |
||||
write_to_fifo(s->fifo, buf); |
||||
return; |
||||
} |
||||
|
||||
/* number of output frames */ |
||||
delta = av_rescale_q(buf->pts - s->pts, inlink->time_base, |
||||
outlink->time_base); |
||||
|
||||
if (delta < 1) { |
||||
/* drop the frame and everything buffered except the first */ |
||||
AVFilterBufferRef *tmp; |
||||
int drop = av_fifo_size(s->fifo)/sizeof(AVFilterBufferRef*); |
||||
|
||||
av_log(ctx, AV_LOG_DEBUG, "Dropping %d frame(s).\n", drop); |
||||
s->drop += drop; |
||||
|
||||
av_fifo_generic_read(s->fifo, &tmp, sizeof(tmp), NULL); |
||||
flush_fifo(s->fifo); |
||||
write_to_fifo(s->fifo, tmp); |
||||
|
||||
avfilter_unref_buffer(buf); |
||||
return; |
||||
} |
||||
|
||||
/* can output >= 1 frames */ |
||||
for (i = 0; i < delta; i++) { |
||||
AVFilterBufferRef *buf_out; |
||||
av_fifo_generic_read(s->fifo, &buf_out, sizeof(buf_out), NULL); |
||||
|
||||
/* duplicate the frame if needed */ |
||||
if (!av_fifo_size(s->fifo) && i < delta - 1) { |
||||
av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n"); |
||||
write_to_fifo(s->fifo, avfilter_ref_buffer(buf_out, AV_PERM_READ)); |
||||
s->dup++; |
||||
} |
||||
|
||||
buf_out->pts = av_rescale_q(s->first_pts, inlink->time_base, |
||||
outlink->time_base) + s->frames_out; |
||||
|
||||
avfilter_start_frame(outlink, buf_out); |
||||
avfilter_draw_slice(outlink, 0, outlink->h, 1); |
||||
avfilter_end_frame(outlink); |
||||
s->frames_out++; |
||||
} |
||||
flush_fifo(s->fifo); |
||||
|
||||
write_to_fifo(s->fifo, buf); |
||||
s->pts = s->first_pts + av_rescale_q(s->frames_out, outlink->time_base, inlink->time_base); |
||||
} |
||||
|
||||
static void null_start_frame(AVFilterLink *link, AVFilterBufferRef *buf) |
||||
{ |
||||
} |
||||
|
||||
static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) |
||||
{ |
||||
} |
||||
|
||||
AVFilter avfilter_vf_fps = { |
||||
.name = "fps", |
||||
.description = NULL_IF_CONFIG_SMALL("Force constant framerate"), |
||||
|
||||
.init = init, |
||||
.uninit = uninit, |
||||
|
||||
.priv_size = sizeof(FPSContext), |
||||
|
||||
.inputs = (AVFilterPad[]) {{ .name = "default", |
||||
.type = AVMEDIA_TYPE_VIDEO, |
||||
.start_frame = null_start_frame, |
||||
.draw_slice = null_draw_slice, |
||||
.end_frame = end_frame, }, |
||||
{ .name = NULL}}, |
||||
.outputs = (AVFilterPad[]) {{ .name = "default", |
||||
.type = AVMEDIA_TYPE_VIDEO, |
||||
.request_frame = request_frame, |
||||
.config_props = config_props}, |
||||
{ .name = NULL}}, |
||||
}; |
||||
Loading…
Reference in new issue