[FFmpeg-devel] [PATCH 2/2] colorchannelmixer filter

Paul B Mahol onemda at gmail.com
Wed Apr 17 23:15:24 CEST 2013


On 4/17/13, Stefano Sabatini <stefasab at gmail.com> wrote:
> On date Wednesday 2013-04-17 00:33:52 +0000, Paul B Mahol encoded:
>> Signed-off-by: Paul B Mahol <onemda at gmail.com>
>> ---
>>  doc/filters.texi                   |  45 ++++++++
>>  libavfilter/Makefile               |   1 +
>>  libavfilter/allfilters.c           |   1 +
>>  libavfilter/vf_colorchannelmixer.c | 229
>> +++++++++++++++++++++++++++++++++++++
>>  4 files changed, 276 insertions(+)
>>  create mode 100644 libavfilter/vf_colorchannelmixer.c
>>
>> diff --git a/doc/filters.texi b/doc/filters.texi
>> index 685791b..6681e52 100644
>> --- a/doc/filters.texi
>> +++ b/doc/filters.texi
>> @@ -2078,6 +2078,51 @@ Adjust red, green and blue highlights (brightest
>> pixels).
>>  Allowed range is from -100 to 100, default is 0.
>>  @end table
>>
>> + at section colorchannelmixer
>> +
>> +Adjust video input frames by re-mixing color channels.
>> +
>
>> +This filter modify a color channel by adding the values associated to
>
> modifies

done

>
>> +the other channels of the same pixels. For example if the value to
>> +modify is red, the output value will be:
>> + at example
>> + at var{red}=@var{red}*@var{rr} + @var{blue}*@var{rb} + @var{green}*@var{rg}
>> + @var{alpha}*@var{ra}
>> + at end example
>> +
>> +The filter accepts the following options:
>> +
>> + at table @option
>> + at item rr
>> + at item rg
>> + at item rb
>> + at item ra
>
>> +Adjust contribution of input red, green, blue and alpha channels for
>> output red channel.
>> +Default is @code{100} for @var{rr}, and @code{0} for @var{rg}, @var{rb}
>> and @var{ra}.
>
> Inconsistent with above example, also I'm for the use of values in the
> range [-2, 2] which is mathematically cleaner (what's so special about
> 100?), and I'm not convinced that you have a real gain in terms of
> syntax.


"Mathematically cleaner" - nonsense.
Inconsistency fixed.

>
>> +
>> + at item gr
>> + at item gg
>> + at item gb
>> + at item ga
>> +Adjust contribution of input red, green, blue and alpha channels for
>> output green channel.
>> +Default is @code{100} for @var{gg}, and @code{0} for @var{gr}, @var{gb}
>> and @var{ga}.
>> +
>> + at item br
>> + at item bg
>> + at item bb
>> + at item ba
>> +Adjust contribution of input red, green, blue and alpha channels for
>> output blue channel.
>> +Default is @code{100} for @var{bb}, and @code{0} for @var{br}, @var{bg}
>> and @var{ba}.
>> +
>> + at item ar
>> + at item ag
>> + at item ab
>> + at item aa
>> +Adjust contribution of input red, green, blue and alpha channels for
>> output alpha channel.
>> +Default is @code{100} for @var{aa}, and @code{0} for @var{ar}, @var{ag}
>> and @var{ab}.
>> +
>> +Allowed ranges are from @code{-200} to @code{200}.
>> + at end table
>
> One or two examples would be nice.

Added.

>
>> +
>>  @section colormatrix
>>
>>  Convert color matrix.
>> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
>> index 0927986..ef40836 100644
>> --- a/libavfilter/Makefile
>> +++ b/libavfilter/Makefile
>> @@ -105,6 +105,7 @@ OBJS-$(CONFIG_BLACKFRAME_FILTER)             +=
>> vf_blackframe.o
>>  OBJS-$(CONFIG_BLEND_FILTER)                  += vf_blend.o
>>  OBJS-$(CONFIG_BOXBLUR_FILTER)                += vf_boxblur.o
>>  OBJS-$(CONFIG_COLORBALANCE_FILTER)           += vf_colorbalance.o
>> +OBJS-$(CONFIG_COLORCHANNELMIXER_FILTER)      += vf_colorchannelmixer.o
>>  OBJS-$(CONFIG_COLORMATRIX_FILTER)            += vf_colormatrix.o
>>  OBJS-$(CONFIG_COPY_FILTER)                   += vf_copy.o
>>  OBJS-$(CONFIG_CROP_FILTER)                   += vf_crop.o
>> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
>> index bebbf2b..a6c8597 100644
>> --- a/libavfilter/allfilters.c
>> +++ b/libavfilter/allfilters.c
>> @@ -103,6 +103,7 @@ void avfilter_register_all(void)
>>      REGISTER_FILTER(BLEND,          blend,          vf);
>>      REGISTER_FILTER(BOXBLUR,        boxblur,        vf);
>>      REGISTER_FILTER(COLORBALANCE,   colorbalance,   vf);
>> +    REGISTER_FILTER(COLORCHANNELMIXER, colorchannelmixer, vf);
>>      REGISTER_FILTER(COLORMATRIX,    colormatrix,    vf);
>>      REGISTER_FILTER(COPY,           copy,           vf);
>>      REGISTER_FILTER(CROP,           crop,           vf);
>> diff --git a/libavfilter/vf_colorchannelmixer.c
>> b/libavfilter/vf_colorchannelmixer.c
>> new file mode 100644
>> index 0000000..164c65b
>> --- /dev/null
>> +++ b/libavfilter/vf_colorchannelmixer.c
>> @@ -0,0 +1,229 @@
>> +/*
>> + * Copyright (c) 2013 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/opt.h"
>> +#include "libavutil/pixdesc.h"
>> +#include "avfilter.h"
>> +#include "drawutils.h"
>> +#include "formats.h"
>> +#include "internal.h"
>> +#include "video.h"
>> +
>> +typedef struct {
>> +    const AVClass *class;
>> +    double rr, rg, rb, ra;
>> +    double gr, gg, gb, ga;
>> +    double br, bg, bb, ba;
>> +    double ar, ag, ab, aa;
>> +
>> +    int RR[256], RG[256], RB[256], RA[256];
>> +    int GR[256], GG[256], GB[256], GA[256];
>> +    int BR[256], BG[256], BB[256], BA[256];
>> +    int AR[256], AG[256], AB[256], AA[256];
>> +
>> +    uint8_t rgba_map[4];
>> +    int step;
>> +} ColorChannelMixerContext;
>> +
>> +#define OFFSET(x) offsetof(ColorChannelMixerContext, x)
>> +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
>> +static const AVOption colorchannelmixer_options[] = {
>> +    { "rr", "set the red gain for the red channel",     OFFSET(rr),
>> AV_OPT_TYPE_DOUBLE, {.dbl=100}, -200, 200, FLAGS },
>> +    { "rg", "set the green gain for the red channel",   OFFSET(rg),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "rb", "set the blue gain for the red channel",    OFFSET(rb),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "ra", "set the alpha gain for the red channel",   OFFSET(ra),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "gr", "set the red gain for the green channel",   OFFSET(gr),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "gg", "set the green gain for the green channel", OFFSET(gg),
>> AV_OPT_TYPE_DOUBLE, {.dbl=100}, -200, 200, FLAGS },
>> +    { "gb", "set the blue gain for the green channel",  OFFSET(gb),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "ga", "set the alpha gain for the green channel", OFFSET(ga),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "br", "set the red gain for the blue channel",    OFFSET(br),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "bg", "set the green gain for the blue channel",  OFFSET(bg),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "bb", "set the blue gain for the blue channel",   OFFSET(bb),
>> AV_OPT_TYPE_DOUBLE, {.dbl=100}, -200, 200, FLAGS },
>> +    { "ba", "set the alpha gain for the blue channel",  OFFSET(ba),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "ar", "set the red gain for the alpha channel",   OFFSET(ar),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "ag", "set the green gain for the alpha channel", OFFSET(ag),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "ab", "set the blue gain for the alpha channel",  OFFSET(ab),
>> AV_OPT_TYPE_DOUBLE, {.dbl=  0}, -200, 200, FLAGS },
>> +    { "aa", "set the alpha gain for the alpha channel", OFFSET(aa),
>> AV_OPT_TYPE_DOUBLE, {.dbl=100}, -200, 200, FLAGS },
>> +    { NULL }
>> +};
>> +
>> +AVFILTER_DEFINE_CLASS(colorchannelmixer);
>> +
>> +static int query_formats(AVFilterContext *ctx)
>> +{
>> +    static const enum AVPixelFormat pix_fmts[] = {
>> +        AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
>> +        AV_PIX_FMT_RGBA,  AV_PIX_FMT_BGRA,
>> +        AV_PIX_FMT_ABGR,  AV_PIX_FMT_ARGB,
>> +        AV_PIX_FMT_0BGR,  AV_PIX_FMT_0RGB,
>> +        AV_PIX_FMT_RGB0,  AV_PIX_FMT_BGR0,
>> +        AV_PIX_FMT_NONE
>> +    };
>> +
>> +    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
>> +    return 0;
>> +}
>> +
>> +static int config_output(AVFilterLink *outlink)
>> +{
>> +    AVFilterContext *ctx = outlink->src;
>> +    ColorChannelMixerContext *cm = ctx->priv;
>> +    const AVPixFmtDescriptor *desc =
>> av_pix_fmt_desc_get(outlink->format);
>> +    int i;
>> +
>> +    for (i = 0; i < 256; i++) {
>> +        cm->RR[i] = i * cm->rr * 0.01;
>> +        cm->RG[i] = i * cm->rg * 0.01;
>> +        cm->RB[i] = i * cm->rb * 0.01;
>> +        cm->RA[i] = i * cm->ra * 0.01;
>> +
>> +        cm->GR[i] = i * cm->gr * 0.01;
>> +        cm->GG[i] = i * cm->gg * 0.01;
>> +        cm->GB[i] = i * cm->gb * 0.01;
>> +        cm->GA[i] = i * cm->ga * 0.01;
>> +
>> +        cm->BR[i] = i * cm->br * 0.01;
>> +        cm->BG[i] = i * cm->bg * 0.01;
>> +        cm->BB[i] = i * cm->bb * 0.01;
>> +        cm->BA[i] = i * cm->ba * 0.01;
>> +
>> +        cm->AR[i] = i * cm->ar * 0.01;
>> +        cm->AG[i] = i * cm->ag * 0.01;
>> +        cm->AB[i] = i * cm->ab * 0.01;
>> +        cm->AA[i] = i * cm->aa * 0.01;
>> +    }
>> +
>> +    ff_fill_rgba_map(cm->rgba_map, outlink->format);
>> +    cm->step = av_get_padded_bits_per_pixel(desc) >> 3;
>> +
>> +    return 0;
>> +}
>> +
>> +static int filter_frame(AVFilterLink *inlink, AVFrame *in)
>> +{
>> +    AVFilterContext *ctx = inlink->dst;
>> +    ColorChannelMixerContext *cm = ctx->priv;
>> +    AVFilterLink *outlink = ctx->outputs[0];
>> +    const uint8_t roffset = cm->rgba_map[0];
>> +    const uint8_t goffset = cm->rgba_map[1];
>> +    const uint8_t boffset = cm->rgba_map[2];
>> +    const uint8_t aoffset = cm->rgba_map[3];
>> +    const uint8_t *srcrow = in->data[0];
>> +    const int step = cm->step;
>> +    uint8_t *dstrow;
>> +    AVFrame *out;
>> +    int i, j;
>> +
>> +    if (av_frame_is_writable(in)) {
>> +        out = in;
>> +    } else {
>> +        out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
>> +        if (!out) {
>> +            av_frame_free(&in);
>> +            return AVERROR(ENOMEM);
>> +        }
>> +        av_frame_copy_props(out, in);
>> +    }
>> +
>
>> +    dstrow = out->data[0];
>> +    switch (outlink->format) {
>> +    case AV_PIX_FMT_0BGR:
>> +    case AV_PIX_FMT_0RGB:
>> +    case AV_PIX_FMT_BGR0:
>> +    case AV_PIX_FMT_BGR24:
>> +    case AV_PIX_FMT_RGB0:
>> +    case AV_PIX_FMT_RGB24:
>> +        for (i = 0; i < outlink->h; i++) {
>> +            const uint8_t *src = srcrow;
>> +            uint8_t *dst = dstrow;
>> +
>> +            for (j = 0; j < outlink->w * step; j += step) {
>> +                const uint8_t rin = src[j + roffset];
>> +                const uint8_t gin = src[j + goffset];
>> +                const uint8_t bin = src[j + boffset];
>> +
>> +                dst[j + roffset] = av_clip_uint8(cm->RR[rin] +
>> cm->RG[gin] + cm->RB[bin]);
>> +                dst[j + goffset] = av_clip_uint8(cm->GR[rin] +
>> cm->GG[gin] + cm->GB[bin]);
>> +                dst[j + boffset] = av_clip_uint8(cm->BR[rin] +
>> cm->BG[gin] + cm->BB[bin]);
>> +                if (in != out && step == 4)
>> +                    dst[j + aoffset] = 0;
>> +            }
>> +
>> +            srcrow += in->linesize[0];
>> +            dstrow += out->linesize[0];
>> +        }
>> +        break;
>> +    case AV_PIX_FMT_ABGR:
>> +    case AV_PIX_FMT_ARGB:
>> +    case AV_PIX_FMT_BGRA:
>> +    case AV_PIX_FMT_RGBA:
>> +        for (i = 0; i < outlink->h; i++) {
>> +            const uint8_t *src = srcrow;
>> +            uint8_t *dst = dstrow;
>> +
>> +            for (j = 0; j < outlink->w * 4; j += 4) {
>> +                const uint8_t rin = src[j + roffset];
>> +                const uint8_t gin = src[j + goffset];
>> +                const uint8_t bin = src[j + boffset];
>> +                const uint8_t ain = src[j + aoffset];
>> +
>> +                dst[j + roffset] = av_clip_uint8(cm->RR[rin] +
>> cm->RG[gin] + cm->RB[bin] + cm->RA[ain]);
>> +                dst[j + goffset] = av_clip_uint8(cm->GR[rin] +
>> cm->GG[gin] + cm->GB[bin] + cm->GA[ain]);
>> +                dst[j + boffset] = av_clip_uint8(cm->BR[rin] +
>> cm->BG[gin] + cm->BB[bin] + cm->BA[ain]);
>> +                dst[j + aoffset] = av_clip_uint8(cm->AR[rin] +
>> cm->AG[gin] + cm->AB[bin] + cm->AA[ain]);
>> +            }
>> +
>> +            srcrow += in->linesize[0];
>> +            dstrow += out->linesize[0];
>> +        }
>
> I suppose this can't be easily factorized with no speedloss...

I could add macros but that is ugly.

>
> [...]
>
> LGTM otherwise apart the 100 vs 1 thing.

Everything else use 100.

> --
> FFmpeg = Faithless and Faithless Magical Pitiful Elfic Gargoyle
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