/*
 * Copyright (c) 2010 Stefano Sabatini
 * Copyright (c) 2008 Vitor Sessak
 *
 * 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
 * transposition filter
 * Based on MPlayer libmpcodecs/vf_rotate.c.
 */

#include "libavutil/intreadwrite.h"
#include "libavutil/pixdesc.h"
#include "libavutil/imgutils.h"
#include "avfilter.h"

typedef struct {
    int hsub, vsub;
    int pixsteps[4];

    /* 0    Rotate by 90 degrees counterclockwise and vflip. */
    /* 1    Rotate by 90 degrees clockwise.                  */
    /* 2    Rotate by 90 degrees counterclockwise.           */
    /* 3    Rotate by 90 degrees clockwise and vflip.        */
    int dir;
} TransContext;

static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
    TransContext *trans = ctx->priv;
    trans->dir = 0;

    if (args)
        sscanf(args, "%d", &trans->dir);

    if (trans->dir < 0 || trans->dir > 3) {
        av_log(ctx, AV_LOG_ERROR, "Invalid value %d not between 0 and 3.\n",
               trans->dir);
        return AVERROR(EINVAL);
    }
    return 0;
}

static int query_formats(AVFilterContext *ctx)
{
    enum PixelFormat pix_fmts[] = {
        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_YUV444P16LE,  PIX_FMT_YUV444P16BE,
        PIX_FMT_NV12,         PIX_FMT_NV21,
        PIX_FMT_RGB8,         PIX_FMT_BGR8,
        PIX_FMT_RGB4_BYTE,    PIX_FMT_BGR4_BYTE,
        PIX_FMT_YUV444P,      PIX_FMT_YUVJ444P,
        PIX_FMT_YUV420P,      PIX_FMT_YUVJ420P,
        PIX_FMT_YUV410P,
        PIX_FMT_YUVA420P,     PIX_FMT_GRAY8,
        PIX_FMT_NONE
    };

    avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
    return 0;
}

static int config_props_output(AVFilterLink *outlink)
{
    AVFilterContext *ctx = outlink->src;
    TransContext *trans = ctx->priv;
    AVFilterLink *inlink = ctx->inputs[0];
    const AVPixFmtDescriptor *pixdesc = &av_pix_fmt_descriptors[outlink->format];

    trans->hsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
    trans->vsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_h;

    av_image_fill_max_pixsteps(trans->pixsteps, NULL, pixdesc);

    outlink->w = inlink->h;
    outlink->h = inlink->w;

    if (inlink->sample_aspect_ratio.num){
        outlink->sample_aspect_ratio = av_div_q((AVRational){1,1}, inlink->sample_aspect_ratio);
    } else
        outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;

    av_log(ctx, AV_LOG_INFO, "w:%d h:%d dir:%d -> w:%d h:%d rotation:%s vflip:%d\n",
           inlink->w, inlink->h, trans->dir, outlink->w, outlink->h,
           trans->dir == 1 || trans->dir == 3 ? "clockwise" : "counterclockwise",
           trans->dir == 0 || trans->dir == 3);
    return 0;
}

static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
{
    AVFilterLink *outlink = inlink->dst->outputs[0];

    outlink->out_buf = avfilter_get_video_buffer(outlink, AV_PERM_WRITE,
                                                 outlink->w, outlink->h);
    outlink->out_buf->pts = picref->pts;

    if (picref->video->sample_aspect_ratio.num == 0) {
        outlink->out_buf->video->sample_aspect_ratio = picref->video->sample_aspect_ratio;
    } else {
        outlink->out_buf->video->sample_aspect_ratio.num = picref->video->sample_aspect_ratio.den;
        outlink->out_buf->video->sample_aspect_ratio.den = picref->video->sample_aspect_ratio.num;
    }

    avfilter_start_frame(outlink, avfilter_ref_buffer(outlink->out_buf, ~0));
}

static void end_frame(AVFilterLink *inlink)
{
    TransContext *trans = inlink->dst->priv;
    AVFilterBufferRef *inpic  = inlink->cur_buf;
    AVFilterBufferRef *outpic = inlink->dst->outputs[0]->out_buf;
    AVFilterLink *outlink = inlink->dst->outputs[0];
    int plane;

    for (plane = 0; outpic->data[plane]; plane++) {
        int hsub = plane == 1 || plane == 2 ? trans->hsub : 0;
        int vsub = plane == 1 || plane == 2 ? trans->vsub : 0;
        int pixstep = trans->pixsteps[plane];
        int inh  = inpic->video->h>>vsub;
        int outw = outpic->video->w>>hsub;
        int outh = outpic->video->h>>vsub;
        uint8_t *out, *in;
        int outlinesize, inlinesize;
        int x, y;

        out = outpic->data[plane]; outlinesize = outpic->linesize[plane];
        in  = inpic ->data[plane]; inlinesize  = inpic ->linesize[plane];

        if (trans->dir&1) {
            in +=  inpic->linesize[plane] * (inh-1);
            inlinesize *= -1;
        }

        if (trans->dir&2) {
            out += outpic->linesize[plane] * (outh-1);
            outlinesize *= -1;
        }

        for (y = 0; y < outh; y++) {
            switch (pixstep) {
            case 1:
                for (x = 0; x < outw; x++)
                    out[x] = in[x*inlinesize + y];
                break;
            case 2:
                for (x = 0; x < outw; x++)
                    *((uint16_t *)(out + 2*x)) = *((uint16_t *)(in + x*inlinesize + y*2));
                break;
            case 3:
                for (x = 0; x < outw; x++) {
                    int32_t v = AV_RB24(in + x*inlinesize + y*3);
                    AV_WB24(out + 3*x, v);
                }
                break;
            case 4:
                for (x = 0; x < outw; x++)
                    *((uint32_t *)(out + 4*x)) = *((uint32_t *)(in + x*inlinesize + y*4));
                break;
            }
            out += outlinesize;
        }
    }

    avfilter_unref_buffer(inpic);
    avfilter_draw_slice(outlink, 0, outpic->video->h, 1);
    avfilter_end_frame(outlink);
    avfilter_unref_buffer(outpic);
}

static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }

AVFilter avfilter_vf_transpose = {
    .name      = "transpose",
    .description = NULL_IF_CONFIG_SMALL("Transpose input video."),

    .init = init,
    .priv_size = sizeof(TransContext),

    .query_formats = query_formats,

    .inputs    = (const AVFilterPad[]) {{ .name      = "default",
                                    .type            = AVMEDIA_TYPE_VIDEO,
                                    .start_frame     = start_frame,
                                    .draw_slice      = null_draw_slice,
                                    .end_frame       = end_frame,
                                    .min_perms       = AV_PERM_READ, },
                                  { .name = NULL}},
    .outputs   = (const AVFilterPad[]) {{ .name      = "default",
                                    .config_props    = config_props_output,
                                    .type            = AVMEDIA_TYPE_VIDEO, },
                                  { .name = NULL}},
};