/* * 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 "interlace.h" #include "internal.h" #include "video.h" #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 void lowpass_line_c(uint8_t *dstp, ptrdiff_t linesize, const uint8_t *srcp, const uint8_t *srcp_above, const uint8_t *srcp_below) { int i; 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; } } 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; } if (!s->lowpass) av_log(ctx, AV_LOG_WARNING, "Lowpass filter is disabled, " "the resulting video will be aliased rather than interlaced.\n"); // same input size outlink->w = inlink->w; outlink->h = inlink->h; outlink->time_base = inlink->time_base; outlink->frame_rate = inlink->frame_rate; // half framerate outlink->time_base.num *= 2; outlink->frame_rate.den *= 2; if (s->lowpass) { s->lowpass_line = lowpass_line_c; if (ARCH_X86) ff_interlace_init_x86(s); } 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(InterlaceContext *s, 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 hsub = desc->log2_chroma_w; int vsub = desc->log2_chroma_h; int plane, j; for (plane = 0; plane < desc->nb_components; plane++) { int cols = (plane == 1 || plane == 2) ? AV_CEIL_RSHIFT(inlink->w, hsub) : inlink->w; int lines = (plane == 1 || plane == 2) ? AV_CEIL_RSHIFT(inlink->h, vsub) : inlink->h; uint8_t *dstp = dst_frame->data[plane]; const uint8_t *srcp = src_frame->data[plane]; av_assert0(cols >= 0 || lines >= 0); lines = (lines + (field_type == FIELD_UPPER)) / 2; if (field_type == FIELD_LOWER) { srcp += src_frame->linesize[plane]; 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 s->lowpass_line(dstp, cols, srcp, srcp_above, srcp_below); dstp += dstp_linesize; srcp += srcp_linesize; } } else { av_image_copy_plane(dstp, dst_frame->linesize[plane] * 2, srcp, src_frame->linesize[plane] * 2, cols, 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; if (s->cur->interlaced_frame) { av_log(ctx, AV_LOG_WARNING, "video is already interlaced, adjusting framerate only\n"); out = av_frame_clone(s->cur); if (!out) return AVERROR(ENOMEM); out->pts /= 2; // adjust pts to new framerate ret = ff_filter_frame(outlink, out); s->got_output = 1; return ret; } 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, 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, 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 ff_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, };