| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * Copyright (c) 2014 Nicholas Robbins | ||
| 3 | * | ||
| 4 | * This file is part of FFmpeg. | ||
| 5 | * | ||
| 6 | * FFmpeg is free software; you can redistribute it and/or | ||
| 7 | * modify it under the terms of the GNU Lesser General Public | ||
| 8 | * License as published by the Free Software Foundation; either | ||
| 9 | * version 2.1 of the License, or (at your option) any later version. | ||
| 10 | * | ||
| 11 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 14 | * Lesser General Public License for more details. | ||
| 15 | * | ||
| 16 | * You should have received a copy of the GNU Lesser General Public | ||
| 17 | * License along with FFmpeg; if not, write to the Free Software | ||
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 19 | */ | ||
| 20 | |||
| 21 | /** | ||
| 22 | * @file | ||
| 23 | * remove judder in video stream | ||
| 24 | * | ||
| 25 | * Algorithm: | ||
| 26 | * - If the old packets had PTS of old_pts[i]. Replace these with new | ||
| 27 | * value based on the running average of the last n=cycle frames. So | ||
| 28 | * | ||
| 29 | * new_pts[i] = Sum(k=i-n+1, i, old_pts[k])/n | ||
| 30 | * + (old_pts[i]-old_pts[i-n])*(n-1)/2n | ||
| 31 | * | ||
| 32 | * For any repeating pattern of length n of judder this will produce | ||
| 33 | * an even progression of PTS's. | ||
| 34 | * | ||
| 35 | * - In order to avoid calculating this sum ever frame, a running tally | ||
| 36 | * is maintained in ctx->new_pts. Each frame the new term at the start | ||
| 37 | * of the sum is added, the one and the end is removed, and the offset | ||
| 38 | * terms (second line in formula above) are recalculated. | ||
| 39 | * | ||
| 40 | * - To aid in this a ringbuffer of the last n-2 PTS's is maintained in | ||
| 41 | * ctx->ringbuff. With the indices of the first two and last two entries | ||
| 42 | * stored in i1, i2, i3, & i4. | ||
| 43 | * | ||
| 44 | * - To ensure that the new PTS's are integers, time_base is divided | ||
| 45 | * by 2n. This removes the division in the new_pts calculation. | ||
| 46 | * | ||
| 47 | * - frame_rate is also multiplied by 2n to allow the frames to fall | ||
| 48 | * where they may in what may now be a VFR output. This produces more | ||
| 49 | * even output then setting frame_rate=1/0 in practice. | ||
| 50 | */ | ||
| 51 | |||
| 52 | #include "libavutil/mem.h" | ||
| 53 | #include "libavutil/opt.h" | ||
| 54 | #include "avfilter.h" | ||
| 55 | #include "internal.h" | ||
| 56 | |||
| 57 | typedef struct DejudderContext { | ||
| 58 | const AVClass *class; | ||
| 59 | int64_t *ringbuff; | ||
| 60 | int i1, i2, i3, i4; | ||
| 61 | int64_t new_pts; | ||
| 62 | int start_count; | ||
| 63 | |||
| 64 | /* options */ | ||
| 65 | int cycle; | ||
| 66 | } DejudderContext; | ||
| 67 | |||
| 68 | #define OFFSET(x) offsetof(DejudderContext, x) | ||
| 69 | #define FLAGS AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM | ||
| 70 | |||
| 71 | static const AVOption dejudder_options[] = { | ||
| 72 | {"cycle", "set the length of the cycle to use for dejuddering", | ||
| 73 | OFFSET(cycle), AV_OPT_TYPE_INT, {.i64 = 4}, 2, 240, .flags = FLAGS}, | ||
| 74 | {NULL} | ||
| 75 | }; | ||
| 76 | |||
| 77 | AVFILTER_DEFINE_CLASS(dejudder); | ||
| 78 | |||
| 79 | ✗ | static int config_out_props(AVFilterLink *outlink) | |
| 80 | { | ||
| 81 | ✗ | AVFilterContext *ctx = outlink->src; | |
| 82 | ✗ | DejudderContext *s = ctx->priv; | |
| 83 | ✗ | AVFilterLink *inlink = outlink->src->inputs[0]; | |
| 84 | |||
| 85 | ✗ | outlink->time_base = av_mul_q(inlink->time_base, av_make_q(1, 2 * s->cycle)); | |
| 86 | ✗ | outlink->frame_rate = av_mul_q(inlink->frame_rate, av_make_q(2 * s->cycle, 1)); | |
| 87 | |||
| 88 | ✗ | av_log(ctx, AV_LOG_VERBOSE, "cycle:%d\n", s->cycle); | |
| 89 | |||
| 90 | ✗ | return 0; | |
| 91 | } | ||
| 92 | |||
| 93 | ✗ | static av_cold int dejudder_init(AVFilterContext *ctx) | |
| 94 | { | ||
| 95 | ✗ | DejudderContext *s = ctx->priv; | |
| 96 | |||
| 97 | ✗ | s->ringbuff = av_calloc(s->cycle + 2, sizeof(*s->ringbuff)); | |
| 98 | ✗ | if (!s->ringbuff) | |
| 99 | ✗ | return AVERROR(ENOMEM); | |
| 100 | |||
| 101 | ✗ | s->new_pts = 0; | |
| 102 | ✗ | s->i1 = 0; | |
| 103 | ✗ | s->i2 = 1; | |
| 104 | ✗ | s->i3 = 2; | |
| 105 | ✗ | s->i4 = 3; | |
| 106 | ✗ | s->start_count = s->cycle + 2; | |
| 107 | |||
| 108 | ✗ | return 0; | |
| 109 | } | ||
| 110 | |||
| 111 | ✗ | static av_cold void dejudder_uninit(AVFilterContext *ctx) | |
| 112 | { | ||
| 113 | ✗ | DejudderContext *s = ctx->priv; | |
| 114 | |||
| 115 | ✗ | av_freep(&(s->ringbuff)); | |
| 116 | ✗ | } | |
| 117 | |||
| 118 | ✗ | static int filter_frame(AVFilterLink *inlink, AVFrame *frame) | |
| 119 | { | ||
| 120 | int k; | ||
| 121 | ✗ | AVFilterContext *ctx = inlink->dst; | |
| 122 | ✗ | AVFilterLink *outlink = ctx->outputs[0]; | |
| 123 | ✗ | DejudderContext *s = ctx->priv; | |
| 124 | ✗ | int64_t *judbuff = s->ringbuff; | |
| 125 | ✗ | int64_t next_pts = frame->pts; | |
| 126 | int64_t offset; | ||
| 127 | |||
| 128 | ✗ | if (next_pts == AV_NOPTS_VALUE) | |
| 129 | ✗ | return ff_filter_frame(outlink, frame); | |
| 130 | |||
| 131 | ✗ | if (s->start_count) { | |
| 132 | ✗ | s->start_count--; | |
| 133 | ✗ | s->new_pts = next_pts * 2 * s->cycle; | |
| 134 | } else { | ||
| 135 | ✗ | if (next_pts < judbuff[s->i2]) { | |
| 136 | ✗ | offset = next_pts + judbuff[s->i3] - judbuff[s->i4] - judbuff[s->i1]; | |
| 137 | ✗ | for (k = 0; k < s->cycle + 2; k++) | |
| 138 | ✗ | judbuff[k] += offset; | |
| 139 | } | ||
| 140 | ✗ | s->new_pts += (s->cycle - 1) * (judbuff[s->i3] - judbuff[s->i1]) | |
| 141 | ✗ | + (s->cycle + 1) * (next_pts - judbuff[s->i4]); | |
| 142 | } | ||
| 143 | |||
| 144 | ✗ | judbuff[s->i2] = next_pts; | |
| 145 | ✗ | s->i1 = s->i2; | |
| 146 | ✗ | s->i2 = s->i3; | |
| 147 | ✗ | s->i3 = s->i4; | |
| 148 | ✗ | s->i4 = (s->i4 + 1) % (s->cycle + 2); | |
| 149 | |||
| 150 | ✗ | frame->pts = s->new_pts; | |
| 151 | |||
| 152 | ✗ | for (k = 0; k < s->cycle + 2; k++) | |
| 153 | ✗ | av_log(ctx, AV_LOG_DEBUG, "%"PRId64"\t", judbuff[k]); | |
| 154 | ✗ | av_log(ctx, AV_LOG_DEBUG, "next=%"PRId64", new=%"PRId64"\n", next_pts, frame->pts); | |
| 155 | |||
| 156 | ✗ | return ff_filter_frame(outlink, frame); | |
| 157 | } | ||
| 158 | |||
| 159 | static const AVFilterPad dejudder_inputs[] = { | ||
| 160 | { | ||
| 161 | .name = "default", | ||
| 162 | .type = AVMEDIA_TYPE_VIDEO, | ||
| 163 | .filter_frame = filter_frame, | ||
| 164 | }, | ||
| 165 | }; | ||
| 166 | |||
| 167 | static const AVFilterPad dejudder_outputs[] = { | ||
| 168 | { | ||
| 169 | .name = "default", | ||
| 170 | .type = AVMEDIA_TYPE_VIDEO, | ||
| 171 | .config_props = config_out_props, | ||
| 172 | }, | ||
| 173 | }; | ||
| 174 | |||
| 175 | const AVFilter ff_vf_dejudder = { | ||
| 176 | .name = "dejudder", | ||
| 177 | .description = NULL_IF_CONFIG_SMALL("Remove judder produced by pullup."), | ||
| 178 | .priv_size = sizeof(DejudderContext), | ||
| 179 | .priv_class = &dejudder_class, | ||
| 180 | FILTER_INPUTS(dejudder_inputs), | ||
| 181 | FILTER_OUTPUTS(dejudder_outputs), | ||
| 182 | .init = dejudder_init, | ||
| 183 | .uninit = dejudder_uninit, | ||
| 184 | }; | ||
| 185 |