/*
* Copyright (c) 2011 Mark Himsley
*
* 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
* video field order filter, heavily influenced by vf_pad.c
*/
/* #define DEBUG */
#include "libavutil/imgutils.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
typedef struct
{
unsigned int dst_tff; ///< output bff/tff
int line_size[4]; ///< bytes of pixel data per line for each plane
} FieldOrderContext;
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
FieldOrderContext *fieldorder = ctx->priv;
const char *tff = "tff";
const char *bff = "bff";
if (!args) {
fieldorder->dst_tff = 1;
} else if (sscanf(args, "%u", &fieldorder->dst_tff) == 1) {
fieldorder->dst_tff = !!fieldorder->dst_tff;
} else if (!strcmp(tff, args)) {
fieldorder->dst_tff = 1;
} else if (!strcmp(bff, args)) {
fieldorder->dst_tff = 0;
} else {
av_log(ctx, AV_LOG_ERROR, "Invalid argument '%s'.\n", args);
return AVERROR(EINVAL);
}
av_log(ctx, AV_LOG_INFO, "output field order: %s\n",
fieldorder->dst_tff ? tff : bff);
return 0;
}
static int query_formats(AVFilterContext *ctx)
{
AVFilterFormats *formats;
enum PixelFormat pix_fmt;
int ret;
/** accept any input pixel format that is not hardware accelerated, not
* a bitstream format, and does not have vertically sub-sampled chroma */
if (ctx->inputs[0]) {
formats = NULL;
for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
if (!( av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_HWACCEL
|| av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_BITSTREAM)
&& av_pix_fmt_descriptors[pix_fmt].nb_components
&& !av_pix_fmt_descriptors[pix_fmt].log2_chroma_h
&& (ret = avfilter_add_format(&formats, pix_fmt)) < 0) {
avfilter_formats_unref(&formats);
return ret;
}
avfilter_formats_ref(formats, &ctx->inputs[0]->out_formats);
avfilter_formats_ref(formats, &ctx->outputs[0]->in_formats);
}
return 0;
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
FieldOrderContext *fieldorder = ctx->priv;
int plane;
/** full an array with the number of bytes that the video
* data occupies per line for each plane of the input video */
for (plane = 0; plane < 4; plane++) {
fieldorder->line_size[plane] = av_image_get_linesize(
inlink->format,
inlink->w,
plane);
}
return 0;
}
static AVFilterBufferRef *get_video_buffer(AVFilterLink *inlink, int perms, int w, int h)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
return avfilter_get_video_buffer(outlink, perms, w, h);
}
static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
AVFilterBufferRef *outpicref;
outpicref = avfilter_ref_buffer(inpicref, ~0);
outlink->out_buf = outpicref;
avfilter_start_frame(outlink, outpicref);
}
static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
{
AVFilterContext *ctx = inlink->dst;
FieldOrderContext *fieldorder = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
AVFilterBufferRef *inpicref = inlink->cur_buf;
/** can only currently do slices if this filter is doing nothing
* because this filter is moving picture content, the output
* slice will contain different video lines than the input slice
* and that complexity will be added later */
if ( !inpicref->video->interlaced
|| inpicref->video->top_field_first == fieldorder->dst_tff) {
avfilter_draw_slice(outlink, y, h, slice_dir);
}
}
static void end_frame(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
FieldOrderContext *fieldorder = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
AVFilterBufferRef *inpicref = inlink->cur_buf;
AVFilterBufferRef *outpicref = outlink->out_buf;
int h, plane, line_step, line_size, line;
uint8_t *cpy_src, *cpy_dst;
if ( inpicref->video->interlaced
&& inpicref->video->top_field_first != fieldorder->dst_tff) {
av_dlog(ctx,
"picture will move %s one line\n",
fieldorder->dst_tff ? "up" : "down");
h = inpicref->video->h;
for (plane = 0; plane < 4 && inpicref->data[plane]; plane++) {
line_step = inpicref->linesize[plane];
line_size = fieldorder->line_size[plane];
cpy_src = inpicref->data[plane];
cpy_dst = outpicref->data[plane];
if (fieldorder->dst_tff) {
/** Move every line up one line, working from
* the top to the bottom of the frame.
* The original top line is lost.
* The new last line is created as a copy of the
* penultimate line from that field. */
for (line = 0; line < h; line++) {
if (1 + line < outpicref->video->h) {
memcpy(cpy_dst, cpy_src + line_step, line_size);
} else {
memcpy(cpy_dst, cpy_src - line_step - line_step, line_size);
}
cpy_src += line_step;
cpy_dst += line_step;
}
} else {
/** Move every line down one line, working from
* the bottom to the top of the frame.
* The original bottom line is lost.
* The new first line is created as a copy of the
* second line from that field. */
cpy_src += (h - 1) * line_step;
cpy_dst += (h - 1) * line_step;
for (line = h - 1; line >= 0 ; line--) {
if (line > 0) {
memcpy(cpy_dst, cpy_src - line_step, line_size);
} else {
memcpy(cpy_dst, cpy_src + line_step + line_step, line_size);
}
cpy_src -= line_step;
cpy_dst -= line_step;
}
}
}
outpicref->video->top_field_first = fieldorder->dst_tff;
avfilter_draw_slice(outlink, 0, h, 1);
} else {
av_dlog(ctx,
"not interlaced or field order already correct\n");
}
avfilter_end_frame(outlink);
avfilter_unref_buffer(inpicref);
}
AVFilter avfilter_vf_fieldorder = {
.name = "fieldorder",
.description = NULL_IF_CONFIG_SMALL("Set the field order."),
.init = init,
.priv_size = sizeof(FieldOrderContext),
.query_formats = query_formats,
.inputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input,
.start_frame = start_frame,
.get_video_buffer = get_video_buffer,
.draw_slice = draw_slice,
.end_frame = end_frame,
.min_perms = AV_PERM_READ,
.rej_perms = AV_PERM_REUSE2|AV_PERM_PRESERVE,},
{ .name = NULL}},
.outputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO, },
{ .name = NULL}},
};