PeerStreamer

/*

 * Copyright (c) 2007 Benoit Fouet

 * Copyright (c) 2010 Stefano Sabatini

 *

 * 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

 */

/**

 * @flip

 * horizontal flip filter

 */

#include "avfilter.h"

#include "libavutil/pixdesc.h"

#include "libavutil/intreadwrite.h"

#include "libavcore/imgutils.h"

typedef struct {

    int max_step[4];    ///< max pixel step for each plane, expressed as a number of bytes

    int hsub, vsub;     ///< chroma subsampling

} FlipContext;

static int query_formats(AVFilterContext *ctx)

{

    static const enum PixelFormat pix_fmts[] = {

        PIX_FMT_RGB48BE,      PIX_FMT_RGB48LE,

        PIX_FMT_ARGB,         PIX_FMT_RGBA,

        PIX_FMT_ABGR,         PIX_FMT_BGRA,

        PIX_FMT_RGB24,        PIX_FMT_BGR24,

        PIX_FMT_RGB565BE,     PIX_FMT_RGB565LE,

        PIX_FMT_RGB555BE,     PIX_FMT_RGB555LE,

        PIX_FMT_BGR565BE,     PIX_FMT_BGR565LE,

        PIX_FMT_BGR555BE,     PIX_FMT_BGR555LE,

        PIX_FMT_GRAY16BE,     PIX_FMT_GRAY16LE,

        PIX_FMT_YUV420P16LE,  PIX_FMT_YUV420P16BE,

        PIX_FMT_YUV422P16LE,  PIX_FMT_YUV422P16BE,

        PIX_FMT_YUV444P16LE,  PIX_FMT_YUV444P16BE,

        PIX_FMT_YUV444P,      PIX_FMT_YUV422P,

        PIX_FMT_YUV420P,      PIX_FMT_YUV411P,

        PIX_FMT_YUV410P,      PIX_FMT_YUV440P,

        PIX_FMT_YUVJ444P,     PIX_FMT_YUVJ422P,

        PIX_FMT_YUVJ420P,     PIX_FMT_YUVJ440P,

        PIX_FMT_YUVA420P,

        PIX_FMT_RGB8,         PIX_FMT_BGR8,

        PIX_FMT_RGB4_BYTE,    PIX_FMT_BGR4_BYTE,

        PIX_FMT_PAL8,         PIX_FMT_GRAY8,

        PIX_FMT_NONE

    };

    avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));

    return 0;

}

static int config_props(AVFilterLink *inlink)

{

    FlipContext *flip = inlink->dst->priv;

    const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];

    av_fill_image_max_pixstep(flip->max_step, NULL, pix_desc);

    flip->hsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_w;

    flip->vsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_h;

    return 0;

}

static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)

{

    FlipContext *flip = inlink->dst->priv;

    AVFilterBufferRef *inpic  = inlink->cur_buf;

    AVFilterBufferRef *outpic = inlink->dst->outputs[0]->out_buf;

    uint8_t *inrow, *outrow;

    int i, j, plane, step, hsub, vsub;

    for (plane = 0; plane < 4 && inpic->data[plane]; plane++) {

        step = flip->max_step[plane];

        hsub = (plane == 1 || plane == 2) ? flip->hsub : 0;

        vsub = (plane == 1 || plane == 2) ? flip->vsub : 0;

        outrow = outpic->data[plane] + (y>>vsub) * outpic->linesize[plane];

        inrow  = inpic ->data[plane] + (y>>vsub) * inpic ->linesize[plane] + ((inlink->w >> hsub) - 1) * step;

        for (i = 0; i < h>>vsub; i++) {

            switch (step) {

            case 1:

            {

                for (j = 0; j < (inlink->w >> hsub); j++)

                    outrow[j] = inrow[-j];

            }

            break;

            case 2:

            {

                uint16_t *outrow16 = (uint16_t *)outrow;

                uint16_t * inrow16 = (uint16_t *) inrow;

                for (j = 0; j < (inlink->w >> hsub); j++)

                    outrow16[j] = inrow16[-j];

            }

            break;

            case 3:

            {

                uint8_t *in  =  inrow;

                uint8_t *out = outrow;

                for (j = 0; j < (inlink->w >> hsub); j++, out += 3, in -= 3) {

                    int32_t v = AV_RB24(in);

                    AV_WB24(out, v);

                }

            }

            break;

            case 4:

            {

                uint32_t *outrow32 = (uint32_t *)outrow;

                uint32_t * inrow32 = (uint32_t *) inrow;

                for (j = 0; j < (inlink->w >> hsub); j++)

                    outrow32[j] = inrow32[-j];

            }

            break;

            default:

                for (j = 0; j < (inlink->w >> hsub); j++)

                    memcpy(outrow + j*step, inrow - j*step, step);

            }

            inrow  += inpic ->linesize[plane];

            outrow += outpic->linesize[plane];

        }

    }

    avfilter_draw_slice(inlink->dst->outputs[0], y, h, slice_dir);

}

AVFilter avfilter_vf_hflip = {

    .name      = "hflip",

    .description = NULL_IF_CONFIG_SMALL("Horizontally flip the input video."),

    .priv_size = sizeof(FlipContext),

    .query_formats = query_formats,

    .inputs    = (AVFilterPad[]) {{ .name            = "default",

                                    .type            = AVMEDIA_TYPE_VIDEO,

                                    .draw_slice      = draw_slice,

                                    .config_props    = config_props,

                                    .min_perms       = AV_PERM_READ, },

                                  { .name = NULL}},

    .outputs   = (AVFilterPad[]) {{ .name            = "default",

                                    .type            = AVMEDIA_TYPE_VIDEO, },

                                  { .name = NULL}},

};