/*

 * Canopus Lossless Codec decoder

 *

 * Copyright (c) 2012-2013 Derek Buitenhuis

 *

 * 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 <inttypes.h>

#include "libavutil/intreadwrite.h"

#include "libavutil/mem.h"

#include "bswapdsp.h"

#include "canopus.h"

#include "get_bits.h"

#include "avcodec.h"

#include "codec_internal.h"

#include "thread.h"

#define VLC_BITS 7

#define VLC_DEPTH 2

typedef struct CLLCContext {

    AVCodecContext *avctx;

    BswapDSPContext bdsp;

    uint8_t *swapped_buf;

    int      swapped_buf_size;

} CLLCContext;

static int read_code_table(CLLCContext *ctx, GetBitContext *gb, VLC *vlc)

{

    uint8_t symbols[256];

    uint8_t bits[256];

    int num_lens, num_codes, num_codes_sum;

    int i, j, count;

    count         = 0;

    num_codes_sum = 0;

    num_lens = get_bits(gb, 5);

    if (num_lens > VLC_BITS * VLC_DEPTH) {

        av_log(ctx->avctx, AV_LOG_ERROR, "To long VLCs %d\n", num_lens);

        return AVERROR_INVALIDDATA;

    }

    for (i = 0; i < num_lens; i++) {

        num_codes      = get_bits(gb, 9);

        num_codes_sum += num_codes;

        if (num_codes_sum > 256) {

            av_log(ctx->avctx, AV_LOG_ERROR,

                   "Too many VLCs (%d) to be read.\n", num_codes_sum);

            return AVERROR_INVALIDDATA;

        }

        for (j = 0; j < num_codes; j++) {

            symbols[count] = get_bits(gb, 8);

            bits[count]    = i + 1;

            count++;

        }

    }

    return ff_vlc_init_from_lengths(vlc, VLC_BITS, count, bits, 1,

                                    symbols, 1, 1, 0, 0, ctx->avctx);

}

/*

 * Unlike the RGB24 read/restore, which reads in a component at a time,

 * ARGB read/restore reads in ARGB quads.

 */

static int read_argb_line(CLLCContext *ctx, GetBitContext *gb, int *top_left,

                          VLC *vlc, uint8_t *outbuf)

{

    uint8_t *dst;

    int pred[4];

    int code;

    int i;

    OPEN_READER(bits, gb);

    dst     = outbuf;

    pred[0] = top_left[0];

    pred[1] = top_left[1];

    pred[2] = top_left[2];

    pred[3] = top_left[3];

    for (i = 0; i < ctx->avctx->width; i++) {

        /* Always get the alpha component */

        UPDATE_CACHE(bits, gb);

        GET_VLC(code, bits, gb, vlc[0].table, VLC_BITS, VLC_DEPTH);

        pred[0] += code;

        dst[0]   = pred[0];

        /* Skip the components if they are  entirely transparent */

        if (dst[0]) {

            /* Red */

            UPDATE_CACHE(bits, gb);

            GET_VLC(code, bits, gb, vlc[1].table, VLC_BITS, VLC_DEPTH);

            pred[1] += code;

            dst[1]   = pred[1];

            /* Green */

            UPDATE_CACHE(bits, gb);

            GET_VLC(code, bits, gb, vlc[2].table, VLC_BITS, VLC_DEPTH);

            pred[2] += code;

            dst[2]   = pred[2];

            /* Blue */

            UPDATE_CACHE(bits, gb);

            GET_VLC(code, bits, gb, vlc[3].table, VLC_BITS, VLC_DEPTH);

            pred[3] += code;

            dst[3]   = pred[3];

        } else {

            dst[1] = 0;

            dst[2] = 0;

            dst[3] = 0;

        }

        dst += 4;

    }

    CLOSE_READER(bits, gb);

    top_left[0]  = outbuf[0];

    /* Only stash components if they are not transparent */

    if (top_left[0]) {

        top_left[1] = outbuf[1];

        top_left[2] = outbuf[2];

        top_left[3] = outbuf[3];

    }

    return 0;

}

static int read_rgb24_component_line(CLLCContext *ctx, GetBitContext *gb,

                                     int *top_left, VLC *vlc, uint8_t *outbuf)

{

    uint8_t *dst;

    int pred, code;

    int i;

    OPEN_READER(bits, gb);

    dst  = outbuf;

    pred = *top_left;

    /* Simultaneously read and restore the line */

    for (i = 0; i < ctx->avctx->width; i++) {

        UPDATE_CACHE(bits, gb);

        GET_VLC(code, bits, gb, vlc->table, VLC_BITS, VLC_DEPTH);

        pred  += code;

        dst[0] = pred;

        dst   += 3;

    }

    CLOSE_READER(bits, gb);

    /* Stash the first pixel */

    *top_left = outbuf[0];

    return 0;

}

static int read_yuv_component_line(CLLCContext *ctx, GetBitContext *gb,

                                   int *top_left, VLC *vlc, uint8_t *outbuf,

                                   int is_chroma)

{

    int pred, code;

    int i;

    OPEN_READER(bits, gb);

    pred = *top_left;

    /* Simultaneously read and restore the line */

    for (i = 0; i < ctx->avctx->width >> is_chroma; i++) {

        UPDATE_CACHE(bits, gb);

        GET_VLC(code, bits, gb, vlc->table, VLC_BITS, VLC_DEPTH);

        pred     += code;

        outbuf[i] = pred;

    }

    CLOSE_READER(bits, gb);

    /* Stash the first pixel */

    *top_left = outbuf[0];

    return 0;

}

static int decode_argb_frame(CLLCContext *ctx, GetBitContext *gb, AVFrame *pic)

{

    AVCodecContext *avctx = ctx->avctx;

    uint8_t *dst;

    int pred[4];

    int ret;

    int i, j;

    VLC vlc[4];

    pred[0] = 0;

    pred[1] = 0x80;

    pred[2] = 0x80;

    pred[3] = 0x80;

    dst = pic->data[0];

    skip_bits(gb, 16);

    /* Read in code table for each plane */

    for (i = 0; i < 4; i++) {

        ret = read_code_table(ctx, gb, &vlc[i]);

        if (ret < 0) {

            for (j = 0; j < i; j++)

                ff_vlc_free(&vlc[j]);

            av_log(ctx->avctx, AV_LOG_ERROR,

                   "Could not read code table %d.\n", i);

            return ret;

        }

    }

    /* Read in and restore every line */

    for (i = 0; i < avctx->height; i++) {

        read_argb_line(ctx, gb, pred, vlc, dst);

        dst += pic->linesize[0];

    }

    for (i = 0; i < 4; i++)

        ff_vlc_free(&vlc[i]);

    return 0;

}

static int decode_rgb24_frame(CLLCContext *ctx, GetBitContext *gb, AVFrame *pic)

{

    AVCodecContext *avctx = ctx->avctx;

    uint8_t *dst;

    int pred[3];

    int ret;

    int i, j;

    VLC vlc[3];

    pred[0] = 0x80;

    pred[1] = 0x80;

    pred[2] = 0x80;

    dst = pic->data[0];

    skip_bits(gb, 16);

    /* Read in code table for each plane */

    for (i = 0; i < 3; i++) {

        ret = read_code_table(ctx, gb, &vlc[i]);

        if (ret < 0) {

            for (j = 0; j < i; j++)

                ff_vlc_free(&vlc[j]);

            av_log(ctx->avctx, AV_LOG_ERROR,

                   "Could not read code table %d.\n", i);

            return ret;

        }

    }

    /* Read in and restore every line */

    for (i = 0; i < avctx->height; i++) {

        for (j = 0; j < 3; j++)

            read_rgb24_component_line(ctx, gb, &pred[j], &vlc[j], &dst[j]);

        dst += pic->linesize[0];

    }

    for (i = 0; i < 3; i++)

        ff_vlc_free(&vlc[i]);

    return 0;

}

static int decode_yuv_frame(CLLCContext *ctx, GetBitContext *gb, AVFrame *pic)

{

    AVCodecContext *avctx = ctx->avctx;

    uint8_t block;

    uint8_t *dst[3];

    int pred[3];

    int ret;

    int i, j;

    VLC vlc[2];

    pred[0] = 0x80;

    pred[1] = 0x80;

    pred[2] = 0x80;

    dst[0] = pic->data[0];

    dst[1] = pic->data[1];

    dst[2] = pic->data[2];

    skip_bits(gb, 8);

    block = get_bits(gb, 8);

    if (block) {

        avpriv_request_sample(ctx->avctx, "Blocked YUV");

        return AVERROR_PATCHWELCOME;

    }

    /* Read in code table for luma and chroma */

    for (i = 0; i < 2; i++) {

        ret = read_code_table(ctx, gb, &vlc[i]);

        if (ret < 0) {

            for (j = 0; j < i; j++)

                ff_vlc_free(&vlc[j]);

            av_log(ctx->avctx, AV_LOG_ERROR,

                   "Could not read code table %d.\n", i);

            return ret;

        }

    }

    /* Read in and restore every line */

    for (i = 0; i < avctx->height; i++) {

        read_yuv_component_line(ctx, gb, &pred[0], &vlc[0], dst[0], 0); /* Y */

        read_yuv_component_line(ctx, gb, &pred[1], &vlc[1], dst[1], 1); /* U */

        read_yuv_component_line(ctx, gb, &pred[2], &vlc[1], dst[2], 1); /* V */

        for (j = 0; j < 3; j++)

            dst[j] += pic->linesize[j];

    }

    for (i = 0; i < 2; i++)

        ff_vlc_free(&vlc[i]);

    return 0;

}

static int cllc_decode_frame(AVCodecContext *avctx, AVFrame *pic,

                             int *got_picture_ptr, AVPacket *avpkt)

{

    CLLCContext *ctx = avctx->priv_data;

    const uint8_t *src = avpkt->data;

    uint32_t info_tag, info_offset;

    int data_size;

    GetBitContext gb;

    int coding_type, ret;

    if (avpkt->size < 4 + 4) {

        av_log(avctx, AV_LOG_ERROR, "Frame is too small %d.\n", avpkt->size);

        return AVERROR_INVALIDDATA;

    }

    info_offset = 0;

    info_tag    = AV_RL32(src);

    if (info_tag == MKTAG('I', 'N', 'F', 'O')) {

        info_offset = AV_RL32(src + 4);

        if (info_offset > UINT32_MAX - 8 || info_offset + 8 > avpkt->size) {

            av_log(avctx, AV_LOG_ERROR,

                   "Invalid INFO header offset: 0x%08"PRIX32" is too large.\n",

                   info_offset);

            return AVERROR_INVALIDDATA;

        }

        ff_canopus_parse_info_tag(avctx, src + 8, info_offset);

        info_offset += 8;

        src         += info_offset;

    }

    data_size = (avpkt->size - info_offset) & ~1;

    /* Make sure our bswap16'd buffer is big enough */

    av_fast_padded_malloc(&ctx->swapped_buf,

                          &ctx->swapped_buf_size, data_size);

    if (!ctx->swapped_buf) {

        av_log(avctx, AV_LOG_ERROR, "Could not allocate swapped buffer.\n");

        return AVERROR(ENOMEM);

    }

    /* bswap16 the buffer since CLLC's bitreader works in 16-bit words */

    ctx->bdsp.bswap16_buf((uint16_t *) ctx->swapped_buf, (uint16_t *) src,

                          data_size / 2);

    if ((ret = init_get_bits8(&gb, ctx->swapped_buf, data_size)) < 0)

        return ret;

    /*

     * Read in coding type. The types are as follows:

     *

     * 0 - YUY2

     * 1 - BGR24 (Triples)

     * 2 - BGR24 (Quads)

     * 3 - BGRA

     */

    coding_type = (AV_RL32(src) >> 8) & 0xFF;

    av_log(avctx, AV_LOG_DEBUG, "Frame coding type: %d\n", coding_type);

    if(get_bits_left(&gb) < avctx->height * avctx->width)

        return AVERROR_INVALIDDATA;

    switch (coding_type) {

    case 0:

        avctx->pix_fmt             = AV_PIX_FMT_YUV422P;

        avctx->bits_per_raw_sample = 8;

        if ((ret = ff_thread_get_buffer(avctx, pic, 0)) < 0)

            return ret;

        ret = decode_yuv_frame(ctx, &gb, pic);

        if (ret < 0)

            return ret;

        break;

    case 1:

    case 2:

        avctx->pix_fmt             = AV_PIX_FMT_RGB24;

        avctx->bits_per_raw_sample = 8;

        if ((ret = ff_thread_get_buffer(avctx, pic, 0)) < 0)

            return ret;

        ret = decode_rgb24_frame(ctx, &gb, pic);

        if (ret < 0)

            return ret;

        break;

    case 3:

        avctx->pix_fmt             = AV_PIX_FMT_ARGB;

        avctx->bits_per_raw_sample = 8;

        if ((ret = ff_thread_get_buffer(avctx, pic, 0)) < 0)

            return ret;

        ret = decode_argb_frame(ctx, &gb, pic);

        if (ret < 0)

            return ret;

        break;

    default:

        av_log(avctx, AV_LOG_ERROR, "Unknown coding type: %d.\n", coding_type);

        return AVERROR_INVALIDDATA;

    }

    *got_picture_ptr = 1;

    return avpkt->size;

}

static av_cold int cllc_decode_close(AVCodecContext *avctx)

{

    CLLCContext *ctx = avctx->priv_data;

    av_freep(&ctx->swapped_buf);

    return 0;

}

static av_cold int cllc_decode_init(AVCodecContext *avctx)

{

    CLLCContext *ctx = avctx->priv_data;

    /* Initialize various context values */

    ctx->avctx            = avctx;

    ctx->swapped_buf      = NULL;

    ctx->swapped_buf_size = 0;

    ff_bswapdsp_init(&ctx->bdsp);

    return 0;

}

const FFCodec ff_cllc_decoder = {

    .p.name         = "cllc",

    CODEC_LONG_NAME("Canopus Lossless Codec"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_CLLC,

    .priv_data_size = sizeof(CLLCContext),

    .init           = cllc_decode_init,

    FF_CODEC_DECODE_CB(cllc_decode_frame),

    .close          = cllc_decode_close,

    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,

};