From 2aad631a818cc49fc30da349c319abfb119adea1 Mon Sep 17 00:00:00 2001 From: Tobias Rapp Date: Wed, 6 Apr 2016 16:25:53 +0200 Subject: avfilter: add readvitc filter Add a filter to scan the top lines of video frames for vertical interval timecode (VITC) information and attach it as metadata keys. Signed-off-by: Tobias Rapp --- Changelog | 1 + MAINTAINERS | 1 + doc/filters.texi | 37 +++++++ libavfilter/Makefile | 1 + libavfilter/allfilters.c | 1 + libavfilter/version.h | 2 +- libavfilter/vf_readvitc.c | 258 ++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 300 insertions(+), 1 deletion(-) create mode 100644 libavfilter/vf_readvitc.c diff --git a/Changelog b/Changelog index 18fdb27d39..6e40739cc9 100644 --- a/Changelog +++ b/Changelog @@ -25,6 +25,7 @@ version : - hash and framehash muxers - colorspace filter - hdcd filter +- readvitc filter version 3.0: - Common Encryption (CENC) MP4 encoding and decoding support diff --git a/MAINTAINERS b/MAINTAINERS index a993a675a2..d2593e52c1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -385,6 +385,7 @@ Filters: vf_neighbor.c Paul B Mahol vf_psnr.c Paul B Mahol vf_random.c Paul B Mahol + vf_readvitc.c Tobias Rapp (CC t.rapp at noa-archive dot com) vf_scale.c Michael Niedermayer vf_separatefields.c Paul B Mahol vf_ssim.c Paul B Mahol diff --git a/doc/filters.texi b/doc/filters.texi index 61307e5838..b17b115288 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -10618,6 +10618,43 @@ less than @code{0}, the filter will try to use a good random seed on a best effort basis. @end table +@section readvitc + +Read vertical interval timecode (VITC) information from the top lines of a +video frame. + +The filter adds frame metadata key @code{lavfi.readvitc.tc_str} with the +timecode value, if a valid timecode has been detected. Further metadata key +@code{lavfi.readvitc.found} is set to 0/1 depending on whether +timecode data has been found or not. + +This filter accepts the following options: + +@table @option +@item scan_max +Set the maximum number of lines to scan for VITC data. If the value is set to +@code{-1} the full video frame is scanned. Default is @code{45}. + +@item thr_b +Set the luma threshold for black. Accepts float numbers in the range [0.0,1.0], +default value is @code{0.2}. The value must be equal or less than @code{thr_w}. + +@item thr_w +Set the luma threshold for white. Accepts float numbers in the range [0.0,1.0], +default value is @code{0.6}. The value must be equal or greater than @code{thr_b}. +@end table + +@subsection Examples + +@itemize +@item +Detect and draw VITC data onto the video frame; if no valid VITC is detected, +draw @code{--:--:--:--} as a placeholder: +@example +ffmpeg -i input.avi -filter:v 'readvitc,drawtext=fontfile=FreeMono.ttf:text=%@{metadata\\:lavfi.readvitc.tc_str\\:--\\\\\\:--\\\\\\:--\\\\\\:--@}:x=(w-tw)/2:y=400-ascent' +@end example +@end itemize + @section remap Remap pixels using 2nd: Xmap and 3rd: Ymap input video stream. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index 2ea8c84a0d..f1f37cb093 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -227,6 +227,7 @@ OBJS-$(CONFIG_PSNR_FILTER) += vf_psnr.o dualinput.o framesync. OBJS-$(CONFIG_PULLUP_FILTER) += vf_pullup.o OBJS-$(CONFIG_QP_FILTER) += vf_qp.o OBJS-$(CONFIG_RANDOM_FILTER) += vf_random.o +OBJS-$(CONFIG_READVITC_FILTER) += vf_readvitc.o OBJS-$(CONFIG_REALTIME_FILTER) += f_realtime.o OBJS-$(CONFIG_REMAP_FILTER) += vf_remap.o framesync.o OBJS-$(CONFIG_REMOVEGRAIN_FILTER) += vf_removegrain.o diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 52d3f619ca..ad6ba21da5 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -247,6 +247,7 @@ void avfilter_register_all(void) REGISTER_FILTER(PULLUP, pullup, vf); REGISTER_FILTER(QP, qp, vf); REGISTER_FILTER(RANDOM, random, vf); + REGISTER_FILTER(READVITC, readvitc, vf); REGISTER_FILTER(REALTIME, realtime, vf); REGISTER_FILTER(REMAP, remap, vf); REGISTER_FILTER(REMOVEGRAIN, removegrain, vf); diff --git a/libavfilter/version.h b/libavfilter/version.h index 48b9d9a6e5..f4ade1cf15 100644 --- a/libavfilter/version.h +++ b/libavfilter/version.h @@ -30,7 +30,7 @@ #include "libavutil/version.h" #define LIBAVFILTER_VERSION_MAJOR 6 -#define LIBAVFILTER_VERSION_MINOR 42 +#define LIBAVFILTER_VERSION_MINOR 43 #define LIBAVFILTER_VERSION_MICRO 100 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ diff --git a/libavfilter/vf_readvitc.c b/libavfilter/vf_readvitc.c new file mode 100644 index 0000000000..7ef8cdae58 --- /dev/null +++ b/libavfilter/vf_readvitc.c @@ -0,0 +1,258 @@ +/* + * Copyright (c) 2016 Tobias Rapp + * + * 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 + * Filter for reading the vertical interval timecode (VITC). + * See also https://en.wikipedia.org/wiki/Vertical_interval_timecode + */ + +#include "libavutil/common.h" +#include "libavutil/internal.h" +#include "libavutil/opt.h" +#include "libavutil/pixdesc.h" +#include "libavutil/timecode.h" +#include "avfilter.h" +#include "formats.h" +#include "internal.h" + +#define LINE_DATA_SIZE 9 + +typedef struct ReadVitcContext { + const AVClass *class; + + int scan_max; + double thr_b; + double thr_w; + + int threshold_black; + int threshold_white; + int threshold_gray; + int grp_width; + uint8_t line_data[LINE_DATA_SIZE]; + char tcbuf[AV_TIMECODE_STR_SIZE]; +} ReadVitcContext; + +#define OFFSET(x) offsetof(ReadVitcContext, x) +#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM + +static const AVOption readvitc_options[] = { + { "scan_max", "maximum line numbers to scan for VITC data", OFFSET(scan_max), AV_OPT_TYPE_INT, {.i64 = 45 }, -1, INT_MAX, FLAGS }, + { "thr_b", "black color threshold", OFFSET(thr_b), AV_OPT_TYPE_DOUBLE, {.dbl = 0.2 }, 0, 1.0, FLAGS }, + { "thr_w", "white color threshold", OFFSET(thr_w), AV_OPT_TYPE_DOUBLE, {.dbl = 0.6 }, 0, 1.0, FLAGS }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(readvitc); + +static uint8_t get_vitc_crc( uint8_t *line ) { + uint8_t crc; + + crc = 0x01 | (line[0] << 2); + crc ^= (line[0] >> 6) | 0x04 | (line[1] << 4); + crc ^= (line[1] >> 4) | 0x10 | (line[2] << 6); + crc ^= (line[2] >> 2) | 0x40; + crc ^= line[3]; + crc ^= 0x01 | (line[4] << 2); + crc ^= (line[4] >> 6) | 0x04 | (line[5] << 4); + crc ^= (line[5] >> 4) | 0x10 | (line[6] << 6); + crc ^= (line[6] >> 2) | 0x40; + crc ^= line[7]; + crc ^= 0x01; + crc = (crc >> 2) | (crc << 6); // rotate byte right by two bits + return crc; +} + +static inline uint8_t get_pit_avg3( uint8_t *line, int i ) { + return ((line[i-1] + line[i] + line[i+1]) / 3); +} + +static int read_vitc_line( ReadVitcContext *ctx, uint8_t *src, int line_size, int width, int height ) +{ + uint8_t *scan_line; + int grp_index, pit_index; + int grp_start_pos; + uint8_t pit_value; + int x, y, res = 0; + + if (ctx->scan_max >= 0) + height = FFMIN(height, ctx->scan_max); + + // scan lines for VITC data, starting from the top + for (y = 0; y < height; y++) { + scan_line = src; + memset(ctx->line_data, 0, LINE_DATA_SIZE); + grp_index = 0; + x = 0; + while ((x < width) && (grp_index < 9)) { + // search next sync pattern + while ((x < width) && (scan_line[x] < ctx->threshold_white)) + x++; + while ((x < width) && (scan_line[x] > ctx->threshold_black)) + x++; + x = FFMAX(x - ((ctx->grp_width+10) / 20), 1); // step back a half pit + grp_start_pos = x; + if ((grp_start_pos + ctx->grp_width) > width) + break; // not enough pixels for reading a whole pit group + pit_value = get_pit_avg3(scan_line, x); + if (pit_value < ctx->threshold_white) + break; // first sync bit mismatch + x = grp_start_pos + ((ctx->grp_width) / 10); + pit_value = get_pit_avg3(scan_line, x); + if (pit_value > ctx->threshold_black ) + break; // second sync bit mismatch + for (pit_index = 0; pit_index <= 7; pit_index++) { + x = grp_start_pos + (((pit_index+2)*ctx->grp_width) / 10); + pit_value = get_pit_avg3(scan_line, x); + if (pit_value > ctx->threshold_gray) + ctx->line_data[grp_index] |= (1 << pit_index); + } + grp_index++; + } + if ((grp_index == 9) && (get_vitc_crc(ctx->line_data) == ctx->line_data[8])) { + res = 1; + break; + } + src += line_size; + } + + return res; +} + +static unsigned bcd2uint(uint8_t high, uint8_t low) +{ + if (high > 9 || low > 9) + return 0; + return 10*high + low; +} + +static char *make_vitc_tc_string(char *buf, uint8_t *line) +{ + unsigned hh = bcd2uint(line[7] & 0x03, line[6] & 0x0f); // 6-bit hours + unsigned mm = bcd2uint(line[5] & 0x07, line[4] & 0x0f); // 7-bit minutes + unsigned ss = bcd2uint(line[3] & 0x07, line[2] & 0x0f); // 7-bit seconds + unsigned ff = bcd2uint(line[1] & 0x03, line[0] & 0x0f); // 6-bit frames + unsigned drop = (line[1] & 0x04); // 1-bit drop flag + snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u", + hh, mm, ss, drop ? ';' : ':', ff); + return buf; +} + +static av_cold int init(AVFilterContext *ctx) +{ + ReadVitcContext *s = ctx->priv; + + s->threshold_black = s->thr_b * UINT8_MAX; + s->threshold_white = s->thr_w * UINT8_MAX; + if (s->threshold_black > s->threshold_white) { + av_log(ctx, AV_LOG_WARNING, "Black color threshold is higher than white color threshold (%g > %g)\n", + s->thr_b, s->thr_w); + return AVERROR(EINVAL); + } + s->threshold_gray = s->threshold_white - ((s->threshold_white - s->threshold_black) / 2); + av_log(ctx, AV_LOG_DEBUG, "threshold_black:%d threshold_white:%d threshold_gray:%d\n", + s->threshold_black, s->threshold_white, s->threshold_gray); + + return 0; +} + +static int config_props(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + ReadVitcContext *s = ctx->priv; + + s->grp_width = inlink->w * 5 / 48; + av_log(ctx, AV_LOG_DEBUG, "w:%d h:%d grp_width:%d scan_max:%d\n", + inlink->w, inlink->h, s->grp_width, s->scan_max); + return 0; +} + +static int query_formats(AVFilterContext *ctx) +{ + static const enum AVPixelFormat pixel_fmts[] = { + AV_PIX_FMT_GRAY8, + AV_PIX_FMT_NV12, + AV_PIX_FMT_NV16, + AV_PIX_FMT_NV21, + AV_PIX_FMT_YUV410P, + AV_PIX_FMT_YUV411P, + AV_PIX_FMT_YUV420P, + AV_PIX_FMT_YUV422P, + AV_PIX_FMT_YUV440P, + AV_PIX_FMT_YUV444P, + AV_PIX_FMT_YUVA420P, + AV_PIX_FMT_YUVA422P, + AV_PIX_FMT_YUVA444P, + AV_PIX_FMT_YUVJ411P, + AV_PIX_FMT_YUVJ420P, + AV_PIX_FMT_YUVJ422P, + AV_PIX_FMT_YUVJ440P, + AV_PIX_FMT_YUVJ444P, + AV_PIX_FMT_NONE + }; + AVFilterFormats *fmts_list = ff_make_format_list(pixel_fmts); + if (!fmts_list) + return AVERROR(ENOMEM); + return ff_set_common_formats(ctx, fmts_list); +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *frame) +{ + AVFilterContext *ctx = inlink->dst; + AVFilterLink *outlink = ctx->outputs[0]; + ReadVitcContext *s = ctx->priv; + int found; + + found = read_vitc_line(s, frame->data[0], frame->linesize[0], inlink->w, inlink->h); + av_dict_set(&frame->metadata, "lavfi.readvitc.found", (found ? "1" : "0"), 0); + if (found) + av_dict_set(&frame->metadata, "lavfi.readvitc.tc_str", make_vitc_tc_string(s->tcbuf, s->line_data), 0); + + return ff_filter_frame(outlink, frame); +} + +static const AVFilterPad inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .filter_frame = filter_frame, + .config_props = config_props, + }, + { NULL } +}; + +static const AVFilterPad outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + }, + { NULL } +}; + +AVFilter ff_vf_readvitc = { + .name = "readvitc", + .description = NULL_IF_CONFIG_SMALL("Read vertical interval timecode and write it to frame metadata."), + .priv_size = sizeof(ReadVitcContext), + .priv_class = &readvitc_class, + .inputs = inputs, + .outputs = outputs, + .init = init, + .query_formats = query_formats, +}; -- cgit v1.2.3