[FFmpeg-devel] [PATCH] smptebars filter

Stefano Sabatini stefasab at gmail.com
Wed Jun 20 11:18:11 CEST 2012


On date Wednesday 2012-06-20 01:54:58 +0000, Paul B Mahol encoded:
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  doc/filters.texi             |   20 ++++
>  libavfilter/Makefile         |    1 +
>  libavfilter/allfilters.c     |    1 +
>  libavfilter/vsrc_smptebars.c |  215 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 237 insertions(+), 0 deletions(-)
>  create mode 100644 libavfilter/vsrc_smptebars.c
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 566fbfc..0c0c490 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -3799,6 +3799,26 @@ the @code{mp=geq} filter:
>  nullsrc=s=256x256, mp=geq=random(1)*255:128:128
>  @end example
>  
> + at section smptebars
> +
> +Generate SMPTE color bars.
> +
> +This source accepts a list of options in the form of
> + at var{key}=@var{value} pairs separated by ":". A description of the
> +accepted options follows.
> +
> + at table @option
> + at item size, s
> +Set the size of the output video.
> +Default is 720x480.
> +
> + at item rate, r
> +Set the video rate, that is the number of frames generated per second.
> +Default is 30.
> +
> + at item sar
> +Set the sample aspect ratio of the sourced video.
> +
>  @c man end VIDEO SOURCES
>  
>  @chapter Video Sinks
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 72bb640..193bfa1 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -136,6 +136,7 @@ OBJS-$(CONFIG_MOVIE_FILTER)                  += src_movie.o
>  OBJS-$(CONFIG_MPTESTSRC_FILTER)              += vsrc_mptestsrc.o
>  OBJS-$(CONFIG_NULLSRC_FILTER)                += vsrc_testsrc.o
>  OBJS-$(CONFIG_RGBTESTSRC_FILTER)             += vsrc_testsrc.o
> +OBJS-$(CONFIG_SMPTEBARS_FILTER)              += vsrc_smptebars.o
>  OBJS-$(CONFIG_TESTSRC_FILTER)                += vsrc_testsrc.o
>  
>  OBJS-$(CONFIG_BUFFERSINK_FILTER)             += sink_buffer.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 35065d5..a4e354b 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -124,6 +124,7 @@ void avfilter_register_all(void)
>      REGISTER_FILTER (MPTESTSRC,   mptestsrc,   vsrc);
>      REGISTER_FILTER (NULLSRC,     nullsrc,     vsrc);
>      REGISTER_FILTER (RGBTESTSRC,  rgbtestsrc,  vsrc);
> +    REGISTER_FILTER (SMPTEBARS,   smptebars,   vsrc);
>      REGISTER_FILTER (TESTSRC,     testsrc,     vsrc);
>  
>      REGISTER_FILTER (BUFFERSINK,  buffersink,  vsink);
> diff --git a/libavfilter/vsrc_smptebars.c b/libavfilter/vsrc_smptebars.c
> new file mode 100644
> index 0000000..70157e8
> --- /dev/null
> +++ b/libavfilter/vsrc_smptebars.c
> @@ -0,0 +1,215 @@
> +/*
> + * Copyright (c) 2012 Paul B Mahol
> + *
> + * 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
> + */
> +
> +#include "libavutil/imgutils.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/parseutils.h"
> +#include "avfilter.h"
> +#include "formats.h"
> +#include "video.h"
> +#include "drawutils.h"
> +
> +typedef struct {
> +    const AVClass *class;
> +    int w, h;
> +    AVRational time_base;
> +    AVRational sar;
> +    char *rate;
> +    int nb_decimals;
> +    FFDrawContext draw;
> +} SMPTEBarsContext;
> +
> +#define OFFSET(x) offsetof(SMPTEBarsContext, x)
> +
> +static const AVOption smptebars_options[]= {
> +    { "size",     "set video size",     OFFSET(w),        AV_OPT_TYPE_IMAGE_SIZE, {.str = "720x480"}, 0, 0 },
> +    { "s",        "set video size",     OFFSET(w),        AV_OPT_TYPE_IMAGE_SIZE, {.str = "720x480"}, 0, 0 },
> +    { "rate",     "set video rate",     OFFSET(rate),     AV_OPT_TYPE_STRING, {.str = "30"},      0, 0 },
> +    { "r",        "set video rate",     OFFSET(rate),     AV_OPT_TYPE_STRING, {.str = "30"},      0, 0 },
> +    { "sar",      "set video sample aspect ratio", OFFSET(sar), AV_OPT_TYPE_RATIONAL, {.dbl= 1},  0, INT_MAX },
> +    { NULL },
> +};
> +
> +static const AVClass smptebars_class = {
> +    .class_name = "smptebars",
> +    .item_name  = av_default_item_name,
> +    .option     = smptebars_options,
> +    .version    = LIBAVUTIL_VERSION_INT,
> +    .category   = AV_CLASS_CATEGORY_FILTER,
> +};
> +
> +static av_cold int smptebars_init(AVFilterContext *ctx, const char *args, void *opaque)
> +{
> +    SMPTEBarsContext *smpte = ctx->priv;
> +    AVRational frame_rate_q;
> +    int ret = 0;
> +
> +    smpte->class = &smptebars_class;
> +
> +    av_opt_set_defaults(smpte);
> +    if ((ret = (av_set_options_string(smpte, args, "=", ":"))) < 0) {
> +        av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
> +        ret = AVERROR(EINVAL);
> +        goto end;
> +    }
> +    if (av_parse_video_rate(&frame_rate_q, smpte->rate) < 0 ||
> +            frame_rate_q.den <= 0 || frame_rate_q.num <= 0) {
> +        av_log(ctx, AV_LOG_ERROR, "Invalid frame rate: %s\n", smpte->rate);
> +        ret = AVERROR(EINVAL);
> +        goto end;
> +    }
> +
> +    smpte->time_base.num = frame_rate_q.den;
> +    smpte->time_base.den = frame_rate_q.num;
> +
> +end:
> +    av_opt_free(smpte);
> +    return ret;
> +}

This code seems the duplicated of that present in vsrc_testsrc.c,
should be possible to easily reuse that (and documentation) for free.

> +
> +static int smptebars_query_formats(AVFilterContext *ctx)
> +{
> +    ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
> +    return 0;
> +}
> +
> +static uint8_t rainbow[7][4] = {
> +    { 191, 191, 191, 255},
> +    { 191, 191,   0, 255},
> +    {   0, 191, 191, 255},
> +    {   0, 191,   0, 255},
> +    { 191,   0, 191, 255},
> +    { 191,   0,   0, 255},
> +    {   0,   0, 191, 255},
> +};
> +

> +static uint8_t wobnair[7][4] = {
> +    {   0,   0, 191, 255},
> +    {   0,   0,   0, 255},
> +    { 191,   0, 191, 255},
> +    {   0,   0,   0, 255},
> +    {   0, 191, 191, 255},
> +    {   0,   0,   0, 255},
> +    { 191, 191, 191, 255},
> +};

the name is funny but pretty obfuscate, please explain what it
represents (in a comment)

> +
> +static uint8_t white[4] = { 255, 255, 255, 255 };
> +static uint8_t black[4] = {   0,   0,   0, 255 };
> +
> +/* made up values */
> +static uint8_t neg4ire[4] = {   7,   7,   7, 255 };
> +static uint8_t pos4ire[4] = {  17,  17,  17, 255 };
> +static uint8_t i_pixel[4] = { 224,   0,   0, 255 };
> +static uint8_t q_pixel[4] = {   0,   0, 176, 255 };
> +
> +static void draw_smptebars(AVFilterContext *ctx, AVFilterBufferRef *picref)
> +{
> +    SMPTEBarsContext *smpte = ctx->priv;
> +    FFDrawColor color;
> +    int r_w, r_h, w_h, p_w, p_h, i, x = 0;
> +
> +    r_w = (smpte->w + 6 ) / 7;
> +    r_h = smpte->h * 2 / 3;
> +    w_h = smpte->h * 3 / 4 - r_h;
> +    p_w = r_w * 5 / 4;
> +    p_h = smpte->h - w_h - r_h;
> +    for (i = 0; i < 7; i++) {
> +        ff_draw_color(&smpte->draw, &color, rainbow[i]);
> +        ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x,   0, r_w, r_h);
> +        ff_draw_color(&smpte->draw, &color, wobnair[i]);
> +        ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x, r_h, r_w, w_h);
> +        x += r_w;
> +    }
> +    x = 0;

> +    ff_draw_color(&smpte->draw, &color, i_pixel);
> +    ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x, r_h + w_h, p_w, p_h);
> +    x += p_w;

macro?

> +    ff_draw_color(&smpte->draw, &color, white);
> +    ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x, r_h + w_h, p_w, p_h);
> +    x += p_w;
> +    ff_draw_color(&smpte->draw, &color, q_pixel);
> +    ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x, r_h + w_h, p_w, p_h);
> +    x += p_w;
> +    ff_draw_color(&smpte->draw, &color, black);
> +    ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x, r_h + w_h, 5 * r_w - x, p_h);
> +    x += 5 * r_w - x;
> +    ff_draw_color(&smpte->draw, &color, neg4ire);
> +    ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x, r_h + w_h, r_w / 3, p_h);
> +    x += r_w / 3;
> +    ff_draw_color(&smpte->draw, &color, black);
> +    ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x, r_h + w_h, r_w / 3, p_h);
> +    x += r_w / 3;
> +    ff_draw_color(&smpte->draw, &color, pos4ire);
> +    ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x, r_h + w_h, r_w / 3, p_h);
> +    x += r_w / 3;
> +    ff_draw_color(&smpte->draw, &color, black);
> +    ff_fill_rectangle(&smpte->draw, &color, picref->data, picref->linesize, x, r_h + w_h, smpte->w - x, p_h);
> +}
> +

> +static int request_frame(AVFilterLink *outlink)
> +{
> +    SMPTEBarsContext *smpte = outlink->src->priv;
> +    AVFilterBufferRef *picref;
> +
> +    picref = ff_get_video_buffer(outlink, AV_PERM_WRITE, smpte->w, smpte->h);
> +    picref->video->sample_aspect_ratio = smpte->sar;
> +
> +    ff_start_frame(outlink, avfilter_ref_buffer(picref, ~0));
> +    draw_smptebars(outlink->src, picref);
> +    ff_draw_slice(outlink, 0, picref->video->h, 1);
> +    ff_end_frame(outlink);
> +    avfilter_unref_buffer(picref);
> +    return 0;
> +}

Again this can be dropped in favor of the common code in vsrc_testsrc.c.

Also, how are you setting the pts?

> +
> +static int config_props(AVFilterLink *outlink)
> +{
> +    AVFilterContext *ctx = outlink->src;
> +    SMPTEBarsContext *smpte = ctx->priv;
> +
> +    ff_draw_init(&smpte->draw, outlink->format, 0);
> +

> +    if (av_image_check_size(smpte->w, smpte->h, 0, ctx) < 0)
> +        return AVERROR(EINVAL);

Is this really required? I wonder becasue I never used it, if required
the check should be moved to the internal code.

[...]
-- 
FFmpeg = Foolish and Faithful Monstrous Problematic Ecletic God


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