/*

 * TechSmith Camtasia decoder

 * Copyright (c) 2004 Konstantin Shishkov

 *

 * 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

 * TechSmith Camtasia decoder

 *

 * Fourcc: TSCC

 *

 * Codec is very simple:

 *  it codes picture (picture difference, really)

 *  with algorithm almost identical to Windows RLE8,

 *  only without padding and with greater pixel sizes,

 *  then this coded picture is packed with ZLib

 *

 * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested

 */

#include "libavutil/mem.h"

#include "avcodec.h"

#include "codec_internal.h"

#include "decode.h"

#include "msrledec.h"

#include "zlib_wrapper.h"

#include <zlib.h>

typedef struct TsccContext {

    AVCodecContext *avctx;

    AVFrame *frame;

    // Bits per pixel

    int bpp;

    // Decompressed data size

    unsigned int decomp_size;

    // Decompression buffer

    unsigned char* decomp_buf;

    GetByteContext gb;

    int height;

    FFZStream zstream;

    uint32_t pal[256];

} CamtasiaContext;

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

                        int *got_frame, AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    CamtasiaContext * const c = avctx->priv_data;

    z_stream *const zstream = &c->zstream.zstream;

    AVFrame *frame = c->frame;

    int ret;

    int palette_has_changed = 0;

    if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {

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

    }

    ret = inflateReset(zstream);

    if (ret != Z_OK) {

        av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);

        return AVERROR_UNKNOWN;

    }

    zstream->next_in   = buf;

    zstream->avail_in  = buf_size;

    zstream->next_out  = c->decomp_buf;

    zstream->avail_out = c->decomp_size;

    ret = inflate(zstream, Z_FINISH);

    // Z_DATA_ERROR means empty picture

    if (ret == Z_DATA_ERROR && !palette_has_changed) {

        return buf_size;

    }

    if ((ret != Z_OK) && (ret != Z_STREAM_END) && (ret != Z_DATA_ERROR)) {

        av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);

        return AVERROR_UNKNOWN;

    }

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

        return ret;

    if (ret != Z_DATA_ERROR) {

        bytestream2_init(&c->gb, c->decomp_buf,

                         c->decomp_size - zstream->avail_out);

        ff_msrle_decode(avctx, frame, c->bpp, &c->gb);

    }

    /* make the palette available on the way out */

    if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {

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

    }

    if ((ret = av_frame_ref(rframe, frame)) < 0)

        return ret;

    *got_frame      = 1;

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

    return buf_size;

}

static av_cold int decode_init(AVCodecContext *avctx)

{

    CamtasiaContext * const c = avctx->priv_data;

    c->avctx = avctx;

    c->height = avctx->height;

    switch(avctx->bits_per_coded_sample){

    case  8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;

    case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;

    case 24:

             avctx->pix_fmt = AV_PIX_FMT_BGR24;

             break;

    case 32: avctx->pix_fmt = AV_PIX_FMT_0RGB32; break;

    default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);

             return AVERROR_PATCHWELCOME;

    }

    c->bpp = avctx->bits_per_coded_sample;

    // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too

    c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;

    /* Allocate decompression buffer */

    if (c->decomp_size) {

        if (!(c->decomp_buf = av_malloc(c->decomp_size))) {

            av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");

            return AVERROR(ENOMEM);

        }

    }

    c->frame = av_frame_alloc();

    if (!c->frame)

        return AVERROR(ENOMEM);

    return ff_inflate_init(&c->zstream, avctx);

}

static av_cold int decode_end(AVCodecContext *avctx)

{

    CamtasiaContext * const c = avctx->priv_data;

    av_freep(&c->decomp_buf);

    av_frame_free(&c->frame);

    ff_inflate_end(&c->zstream);

    return 0;

}

const FFCodec ff_tscc_decoder = {

    .p.name         = "camtasia",

    CODEC_LONG_NAME("TechSmith Screen Capture Codec"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_TSCC,

    .priv_data_size = sizeof(CamtasiaContext),

    .init           = decode_init,

    .close          = decode_end,

    FF_CODEC_DECODE_CB(decode_frame),

    .p.capabilities = AV_CODEC_CAP_DR1,

    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,

};