/*
* Copyright (c) 2015 Himangi Saraogi <himangi774@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file detelecine filter.
*/
#include "libavutil/avstring.h"
#include "libavutil/imgutils.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
typedef struct {
const AVClass *class;
int first_field;
char *pattern;
int start_frame;
unsigned int pattern_pos;
unsigned int nskip_fields;
int64_t start_time;
AVRational pts;
AVRational ts_unit;
int occupied;
int nb_planes;
int planeheight[4];
int stride[4];
AVFrame *frame;
AVFrame *temp;
} DetelecineContext;
#define OFFSET(x) offsetof(DetelecineContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
static const AVOption detelecine_options[] = {
{"first_field", "select first field", OFFSET(first_field), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, "field"},
{"top", "select top field first", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "field"},
{"t", "select top field first", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "field"},
{"bottom", "select bottom field first", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "field"},
{"b", "select bottom field first", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "field"},
{"pattern", "pattern that describe for how many fields a frame is to be displayed", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str="23"}, 0, 0, FLAGS},
{"start_frame", "position of first frame with respect to the pattern if stream is cut", OFFSET(start_frame), AV_OPT_TYPE_INT, {.i64=0}, 0, 13, FLAGS},
{NULL}
};
AVFILTER_DEFINE_CLASS(detelecine);
static av_cold int init(AVFilterContext *ctx)
{
DetelecineContext *s = ctx->priv;
const char *p;
int max = 0;
av_log(ctx, AV_LOG_ERROR, "No pattern provided.\n");
return AVERROR_INVALIDDATA;
}
for (p = s->pattern; *p; p++) {
if (!av_isdigit(*p)) {
av_log(ctx, AV_LOG_ERROR, "Provided pattern includes non-numeric characters.\n");
return AVERROR_INVALIDDATA;
}
max = FFMAX(*p - '0', max);
s->pts.num += *p - '0';
s->pts.den += 2;
}
s->nskip_fields = 0;
s->pattern_pos = 0;
s->start_time = AV_NOPTS_VALUE;
if (s->start_frame != 0) {
int nfields = 0;
for (p = s->pattern; *p; p++) {
nfields += *p - '0';
s->pattern_pos++;
if (nfields >= 2*s->start_frame) {
s->nskip_fields = nfields - 2*s->start_frame;
break;
}
}
}
av_log(ctx, AV_LOG_INFO, "Detelecine pattern %s removes up to %d frames per frame, pts advance factor: %d/%d\n",
s->pattern, (max + 1) / 2, s->pts.num, s->pts.den);
return 0;
}
static int query_formats(AVFilterContext *ctx)
{
AVFilterFormats *pix_fmts = NULL;
int fmt;
for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL ||
desc->flags & AV_PIX_FMT_FLAG_PAL ||
desc->flags & AV_PIX_FMT_FLAG_BITSTREAM))
ff_add_format(&pix_fmts, fmt);
}
return ff_set_common_formats(ctx, pix_fmts);
}
static int config_input(AVFilterLink *inlink)
{
DetelecineContext *s = inlink->dst->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
int ret;
s->temp = ff_get_video_buffer(inlink, inlink->w, inlink->h);
if (!s->temp)
return AVERROR(ENOMEM);
s->frame = ff_get_video_buffer(inlink, inlink->w, inlink->h);
if (!s->frame)
return AVERROR(ENOMEM);
if ((ret = av_image_fill_linesizes(s->stride, inlink->format, inlink->w)) < 0)
return ret;
s->planeheight[1] = s->planeheight[2] = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
s->planeheight[0] = s->planeheight[3] = inlink->h;
s->nb_planes = av_pix_fmt_count_planes(inlink->format);
return 0;
}
static int config_output(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
DetelecineContext *s = ctx->priv;
const AVFilterLink *inlink = ctx->inputs[0];
AVRational fps = inlink->frame_rate;
if (!fps.num || !fps.den) {
av_log(ctx, AV_LOG_ERROR, "The input needs a constant frame rate; "
"current rate of %d/%d is invalid\n", fps.num, fps.den);
return AVERROR(EINVAL);
}
fps = av_mul_q(fps, av_inv_q(s->pts));
av_log(ctx, AV_LOG_VERBOSE, "FPS: %d/%d -> %d/%d\n",
inlink->frame_rate.num, inlink->frame_rate.den, fps.num, fps.den);
outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;
outlink->frame_rate = fps;
outlink->time_base = av_mul_q(inlink->time_base, s->pts);
av_log(ctx, AV_LOG_VERBOSE, "TB: %d/%d -> %d/%d\n",
inlink->time_base.num, inlink->time_base.den, outlink->time_base.num, outlink->time_base.den);
s->ts_unit = av_inv_q(av_mul_q(fps, outlink->time_base));
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
DetelecineContext *s = ctx->priv;
int i, len = 0, ret = 0, out = 0;
if (s->start_time == AV_NOPTS_VALUE)
s->start_time = inpicref->pts;
if (s->nskip_fields >= 2) {
s->nskip_fields -= 2;
return 0;
} else if (s->nskip_fields >= 1) {
if (s->occupied) {
s->occupied = 0;
s->nskip_fields--;
}
else {
for (i = 0; i < s->nb_planes; i++) {
av_image_copy_plane(s->temp->data[i], s->temp->linesize[i],
inpicref->data[i], inpicref->linesize[i],
s->stride[i],
s->planeheight[i]);
}
s->occupied = 1;
s->nskip_fields--;
return 0;
}
}
if (s->nskip_fields == 0) {
while(!len && s->pattern[s->pattern_pos]) {
len = s->pattern[s->pattern_pos] - '0';
s->pattern_pos++;
}
if (!s->pattern[s->pattern_pos])
s->pattern_pos = 0;
if(!len) { // do not output any field as the entire pattern is zero
av_frame_free(&inpicref);
return 0;
}
if (s->occupied) {
for (i = 0; i < s->nb_planes; i++) {
// fill in the EARLIER field from the new pic
av_image_copy_plane(s->frame->data[i] + s->frame->linesize[i] * s->first_field,
s->frame->linesize[i] * 2,
inpicref->data[i] + inpicref->linesize[i] * s->first_field,
inpicref->linesize[i] * 2,
s->stride[i],
(s->planeheight[i] - s->first_field + 1) / 2);
// fill in the LATER field from the buffered pic
av_image_copy_plane(s->frame->data[i] + s->frame->linesize[i] * !s->first_field,
s->frame->linesize[i] * 2,
s->temp->data[i] + s->temp->linesize[i] * !s->first_field,
s->temp->linesize[i] * 2,
s->stride[i],
(s->planeheight[i] - !s->first_field + 1) / 2);
}
len -= 2;
for (i = 0; i < s->nb_planes; i++) {
av_image_copy_plane(s->temp->data[i], s->temp->linesize[i],
inpicref->data[i], inpicref->linesize[i],
s->stride[i],
s->planeheight[i]);
}
s->occupied = 1;
out = 1;
} else {
if (len >= 2) {
// output THIS image as-is
for (i = 0; i < s->nb_planes; i++)
av_image_copy_plane(s->frame->data[i], s->frame->linesize[i],
inpicref->data[i], inpicref->linesize[i],
s->stride[i],
s->planeheight[i]);
len -= 2;
out = 1;
} else if (len == 1) {
// fill in the EARLIER field from the new pic
for (i = 0; i < s->nb_planes; i++) {
av_image_copy_plane(s->frame->data[i] +
s->frame->linesize[i] * s->first_field,
s->frame->linesize[i] * 2,
inpicref->data[i] +
inpicref->linesize[i] * s->first_field,
inpicref->linesize[i] * 2, s->stride[i],
(s->planeheight[i] - s->first_field + 1) / 2);
}
// TODO: not sure about the other field
len--;
out = 1;
}
}
if (len == 1 && s->occupied)
{
len--;
s->occupied = 0;
}
}
s->nskip_fields = len;
if (out) {
AVFrame *frame = av_frame_clone(s->frame);
if (!frame) {
av_frame_free(&inpicref);
return AVERROR(ENOMEM);
}
av_frame_copy_props(frame, inpicref);
frame->pts = ((s->start_time == AV_NOPTS_VALUE) ? 0 : s->start_time) +
av_rescale(outlink->frame_count, s->ts_unit.num,
s->ts_unit.den);
ret = ff_filter_frame(outlink, frame);
}
av_frame_free(&inpicref);
return ret;
}
static av_cold void uninit(AVFilterContext *ctx)
{
DetelecineContext *s = ctx->priv;
av_frame_free(&s->temp);
av_frame_free(&s->frame);
}
static const AVFilterPad detelecine_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
.config_props = config_input,
},
{ NULL }
};
static const AVFilterPad detelecine_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output,
},
{ NULL }
};
AVFilter ff_vf_detelecine = {
.name = "detelecine",
.description = NULL_IF_CONFIG_SMALL("Apply an inverse telecine pattern."),
.priv_size = sizeof(DetelecineContext),
.priv_class = &detelecine_class,
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.inputs = detelecine_inputs,
.outputs = detelecine_outputs,
};