From 3fce13679837ce9b43b50a4843c30ee989566bf8 Mon Sep 17 00:00:00 2001 From: Vittorio Giovara Date: Tue, 12 Mar 2013 11:35:21 +0100 Subject: lavfi: new interlace filter Signed-off-by: Anton Khirnov --- libavfilter/vf_interlace.c | 252 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 252 insertions(+) create mode 100755 libavfilter/vf_interlace.c (limited to 'libavfilter/vf_interlace.c') diff --git a/libavfilter/vf_interlace.c b/libavfilter/vf_interlace.c new file mode 100755 index 0000000000..d3c3d4da31 --- /dev/null +++ b/libavfilter/vf_interlace.c @@ -0,0 +1,252 @@ +/* + * This file is part of Libav. + * + * Libav is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 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 General Public License for more details. + * + * You should have received a copy of the GNU 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 + * progressive to interlaced content filter, inspired by heavy debugging of tinterlace filter + */ + +#include "libavutil/common.h" +#include "libavutil/opt.h" +#include "libavutil/imgutils.h" +#include "libavutil/avassert.h" + +#include "formats.h" +#include "avfilter.h" +#include "internal.h" +#include "video.h" + +enum ScanMode { + MODE_TFF = 0, + MODE_BFF = 1, +}; + +enum FieldType { + FIELD_UPPER = 0, + FIELD_LOWER = 1, +}; + +typedef struct { + const AVClass *class; + enum ScanMode scan; // top or bottom field first scanning + int lowpass; // enable or disable low pass filterning + AVFrame *cur, *next; // the two frames from which the new one is obtained + int got_output; // signal an output frame is reday to request_frame() +} InterlaceContext; + +#define OFFSET(x) offsetof(InterlaceContext, x) +#define V AV_OPT_FLAG_VIDEO_PARAM +static const AVOption options[] = { + { "scan", "scanning mode", OFFSET(scan), + AV_OPT_TYPE_INT, {.i64 = MODE_TFF }, 0, 1, .flags = V, .unit = "scan" }, + { "tff", "top field first", 0, + AV_OPT_TYPE_CONST, {.i64 = MODE_TFF }, INT_MIN, INT_MAX, .flags = V, .unit = "scan" }, + { "bff", "bottom field first", 0, + AV_OPT_TYPE_CONST, {.i64 = MODE_BFF }, INT_MIN, INT_MAX, .flags = V, .unit = "scan" }, + { "lowpass", "enable vertical low-pass filter", OFFSET(lowpass), + AV_OPT_TYPE_INT, {.i64 = 1 }, 0, 1, .flags = V }, + { NULL } +}; + +static const AVClass class = { + .class_name = "interlace filter", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + + +static const enum AVPixelFormat formats_supported[] = { + AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P, + AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUVA420P, + AV_PIX_FMT_GRAY8, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, + AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_NONE +}; + +static int query_formats(AVFilterContext *ctx) +{ + ff_set_common_formats(ctx, ff_make_format_list(formats_supported)); + return 0; +} + +static av_cold void uninit(AVFilterContext *ctx) +{ + InterlaceContext *s = ctx->priv; + + av_frame_free(&s->cur); + av_frame_free(&s->next); + + av_opt_free(s); +} + +static int config_out_props(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + AVFilterLink *inlink = outlink->src->inputs[0]; + InterlaceContext *s = ctx->priv; + + if (inlink->h < 2) { + av_log(ctx, AV_LOG_ERROR, "input video height is too small\n"); + return AVERROR_INVALIDDATA; + } + // same input size + outlink->w = inlink->w; + outlink->h = inlink->h; + outlink->time_base = inlink->time_base; + // half framerate + outlink->time_base.num *= 2; + + av_log(ctx, AV_LOG_VERBOSE, "%s interlacing %s lowpass filter\n", + s->scan == MODE_TFF ? "tff" : "bff", (s->lowpass) ? "with" : "without"); + + return 0; +} + +static void copy_picture_field(AVFrame *src_frame, AVFrame *dst_frame, + AVFilterLink *inlink, enum FieldType field_type, + int lowpass) +{ + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); + int vsub = desc->log2_chroma_h; + int plane, i, j; + + for (plane = 0; plane < desc->nb_components; plane++) { + int lines = (plane == 1 || plane == 2) ? inlink->h >> vsub : inlink->h; + int linesize = av_image_get_linesize(inlink->format, inlink->w, plane); + uint8_t *dstp = dst_frame->data[plane]; + const uint8_t *srcp = src_frame->data[plane]; + + av_assert0(linesize >= 0); + + lines /= 2; + if (field_type == FIELD_LOWER) + srcp += src_frame->linesize[plane]; + if (field_type == FIELD_LOWER) + dstp += dst_frame->linesize[plane]; + if (lowpass) { + int srcp_linesize = src_frame->linesize[plane] * 2; + int dstp_linesize = dst_frame->linesize[plane] * 2; + for (j = lines; j > 0; j--) { + const uint8_t *srcp_above = srcp - src_frame->linesize[plane]; + const uint8_t *srcp_below = srcp + src_frame->linesize[plane]; + if (j == lines) + srcp_above = srcp; // there is no line above + if (j == 1) + srcp_below = srcp; // there is no line below + for (i = 0; i < linesize; i++) { + // this calculation is an integer representation of + // '0.5 * current + 0.25 * above + 0.25 + below' + // '1 +' is for rounding. + dstp[i] = (1 + srcp[i] + srcp[i] + srcp_above[i] + srcp_below[i]) >> 2; + } + dstp += dstp_linesize; + srcp += srcp_linesize; + } + } else { + av_image_copy_plane(dstp, dst_frame->linesize[plane] * 2, + srcp, src_frame->linesize[plane] * 2, + linesize, lines); + } + } +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *buf) +{ + AVFilterContext *ctx = inlink->dst; + AVFilterLink *outlink = ctx->outputs[0]; + InterlaceContext *s = ctx->priv; + AVFrame *out; + int tff, ret; + + av_frame_free(&s->cur); + s->cur = s->next; + s->next = buf; + + /* we need at least two frames */ + if (!s->cur || !s->next) + return 0; + + tff = (s->scan == MODE_TFF); + out = ff_get_video_buffer(outlink, outlink->w, outlink->h); + if (!out) + return AVERROR(ENOMEM); + + av_frame_copy_props(out, s->cur); + out->interlaced_frame = 1; + out->top_field_first = tff; + out->pts /= 2; // adjust pts to new framerate + + /* copy upper/lower field from cur */ + copy_picture_field(s->cur, out, inlink, tff ? FIELD_UPPER : FIELD_LOWER, s->lowpass); + av_frame_free(&s->cur); + + /* copy lower/upper field from next */ + copy_picture_field(s->next, out, inlink, tff ? FIELD_LOWER : FIELD_UPPER, s->lowpass); + av_frame_free(&s->next); + + ret = ff_filter_frame(outlink, out); + s->got_output = 1; + + return ret; +} + +static int request_frame(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + InterlaceContext *s = ctx->priv; + int ret = 0; + + s->got_output = 0; + while (ret >= 0 && !s->got_output) + ret = ff_request_frame(ctx->inputs[0]); + + return ret; +} + +static const AVFilterPad inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = config_out_props, + .request_frame = request_frame, + }, + { NULL } +}; + +AVFilter avfilter_vf_interlace = { + .name = "interlace", + .description = NULL_IF_CONFIG_SMALL("Convert progressive video into interlaced."), + .uninit = uninit, + + .priv_class = &class, + .priv_size = sizeof(InterlaceContext), + .query_formats = query_formats, + + .inputs = inputs, + .outputs = outputs, +}; + -- cgit v1.2.3