/*

 * Quicktime Planar RGB (8BPS) Video Decoder

 * Copyright (C) 2003 Roberto Togni

 *

 * 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

 * QT 8BPS Video Decoder by Roberto Togni

 * For more information about the 8BPS format, visit:

 *   http://www.pcisys.net/~melanson/codecs/

 *

 * Supports: PAL8 (RGB 8bpp, paletted)

 *         : GBRP (RGB 24bpp)

 *         : GBRAP (RGB 32bpp, 4th plane is alpha)

 */

#include <string.h>

#include "libavutil/intreadwrite.h"

#include "libavutil/internal.h"

#include "avcodec.h"

#include "codec_internal.h"

#include "decode.h"

typedef struct EightBpsContext {

    AVCodecContext *avctx;

    uint8_t planes;

    uint8_t planemap[4];

    uint32_t pal[256];

} EightBpsContext;

static int decode_frame(AVCodecContext *avctx, AVFrame *frame,

                        int *got_frame, AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size       = avpkt->size;

    EightBpsContext * const c = avctx->priv_data;

    const uint8_t *encoded = buf;

    uint8_t *pixptr, *pixptr_end;

    unsigned int height = avctx->height; // Real image height

    unsigned int dlen, p, row;

    const uint8_t *lp, *dp, *ep;

    uint8_t count;

    const uint8_t *planemap = c->planemap;

    unsigned int planes = c->planes;

    int ret;

    if (buf_size < planes * height * (2 + 2*((avctx->width+128)/129)))

        return AVERROR_INVALIDDATA;

    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

        return ret;

    ep = encoded + buf_size;

    /* Set data pointer after line lengths */

    dp = encoded + planes * (height << 1);

    for (p = 0; p < planes; p++) {

        const int pi = planemap[p];

        /* Lines length pointer for this plane */

        lp = encoded + p * (height << 1);

        /* Decode a plane */

        for (row = 0; row < height; row++) {

            pixptr = frame->data[pi] + row * frame->linesize[pi];

            pixptr_end = pixptr + frame->linesize[pi];

            if (ep - lp < row * 2 + 2)

                return AVERROR_INVALIDDATA;

            dlen = AV_RB16(lp + row * 2);

            /* Decode a row of this plane */

            while (dlen > 0) {

                if (ep - dp <= 1)

                    return AVERROR_INVALIDDATA;

                if ((count = *dp++) <= 127) {

                    count++;

                    dlen -= count + 1;

                    if (pixptr_end - pixptr < count)

                        break;

                    if (ep - dp < count)

                        return AVERROR_INVALIDDATA;

                    memcpy(pixptr, dp, count);

                    pixptr += count;

                    dp += count;

                } else {

                    count = 257 - count;

                    if (pixptr_end - pixptr < count)

                        break;

                    memset(pixptr, dp[0], count);

                    pixptr += count;

                    dp++;

                    dlen -= 2;

                }

            }

        }

    }

    if (avctx->bits_per_coded_sample <= 8) {

        ff_copy_palette(c->pal, avpkt, avctx);

        memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);

    }

    *got_frame = 1;

    /* always report that the buffer was completely consumed */

    return buf_size;

}

static av_cold int decode_init(AVCodecContext *avctx)

{

    EightBpsContext * const c = avctx->priv_data;

    c->avctx       = avctx;

    switch (avctx->bits_per_coded_sample) {

    case 8:

        avctx->pix_fmt = AV_PIX_FMT_PAL8;

        c->planes      = 1;

        c->planemap[0] = 0; // 1st plane is palette indexes

        break;

    case 24:

        avctx->pix_fmt = AV_PIX_FMT_GBRP;

        c->planes      = 3;

        c->planemap[0] = 2; // 1st plane is red

        c->planemap[1] = 0; // 2nd plane is green

        c->planemap[2] = 1; // 3rd plane is blue

        break;

    case 32:

        avctx->pix_fmt = AV_PIX_FMT_GBRAP;

        c->planes      = 4;

        break;

    default:

        av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",

               avctx->bits_per_coded_sample);

        return AVERROR_INVALIDDATA;

    }

    if (avctx->pix_fmt == AV_PIX_FMT_GBRAP) {

        c->planemap[0] = 2; // 1st plane is red

        c->planemap[1] = 0; // 2nd plane is green

        c->planemap[2] = 1; // 3rd plane is blue

        c->planemap[3] = 3; // 4th plane is alpha

    }

    return 0;

}

const FFCodec ff_eightbps_decoder = {

    .p.name         = "8bps",

    CODEC_LONG_NAME("QuickTime 8BPS video"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_8BPS,

    .priv_data_size = sizeof(EightBpsContext),

    .init           = decode_init,

    FF_CODEC_DECODE_CB(decode_frame),

    .p.capabilities = AV_CODEC_CAP_DR1,

};