/*

 * Canopus HQ/HQA decoder

 *

 * 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 <stdint.h>

#include "libavutil/attributes.h"

#include "libavutil/mem_internal.h"

#include "libavutil/thread.h"

#include "avcodec.h"

#include "bytestream.h"

#include "canopus.h"

#include "codec_internal.h"

#include "decode.h"

#include "get_bits.h"

#include "hq_common.h"

#include "hq_hqadata.h"

#include "hq_hqadsp.h"

#include "vlc.h"

/* HQ/HQA slices are a set of macroblocks belonging to a frame, and

 * they usually form a pseudorandom pattern (probably because it is

 * nicer to display on partial decode).

 *

 * For HQA it just happens that each slice is on every 8th macroblock,

 * but they can be on any frame width like

 *   X.......X.

 *   ......X...

 *   ....X.....

 *   ..X.......

 * etc.

 *

 * The original decoder has special handling for edge macroblocks,

 * while lavc simply aligns coded_width and coded_height.

 */

typedef struct HQContext {

    AVCodecContext *avctx;

    HQDSPContext hqhqadsp;

    DECLARE_ALIGNED(16, int16_t, block)[12][64];

} HQContext;

static const int32_t *hq_quants[NUM_HQ_QUANTS][2][4];

static RL_VLC_ELEM hq_ac_rvlc[1184];

static inline void put_blocks(HQContext *c, AVFrame *pic,

                              int plane, int x, int y, int ilace,

                              int16_t *block0, int16_t *block1)

{

    uint8_t *p = pic->data[plane] + x;

    c->hqhqadsp.idct_put(p + y * pic->linesize[plane],

                         pic->linesize[plane] << ilace, block0);

    c->hqhqadsp.idct_put(p + (y + (ilace ? 1 : 8)) * pic->linesize[plane],

                         pic->linesize[plane] << ilace, block1);

}

static int hq_decode_block(HQContext *c, GetBitContext *gb, int16_t block[64],

                           int qsel, int is_chroma, int is_hqa)

{

    const int32_t *q;

    if (!is_hqa) {

        block[0] = get_sbits(gb, 9) * 64;

        q = hq_quants[qsel][is_chroma][get_bits(gb, 2)];

    } else {

        q = hq_quants[qsel][is_chroma][get_bits(gb, 2)];

        block[0] = get_sbits(gb, 9) * 64;

    }

    OPEN_READER(re, gb);

    for (int pos = 0;;) {

        int level, run;

        UPDATE_CACHE(re, gb);

        GET_RL_VLC(level, run, re, gb, hq_ac_rvlc, 9, 2, 0);

        if (run == HQ_AC_INVALID_RUN) {

            CLOSE_READER(re, gb);

            return AVERROR_INVALIDDATA;

        }

        pos += run;

        if (pos >= 64)

            break;

        block[ff_zigzag_direct[pos]] = (int)(level * (unsigned)q[pos]) >> 12;

    }

    CLOSE_READER(re, gb);

    return 0;

}

static int hq_decode_mb(HQContext *c, AVFrame *pic,

                        GetBitContext *gb, int x, int y)

{

    int qgroup, flag;

    int i, ret;

    memset(c->block, 0, 8 * sizeof(c->block[0]));

    qgroup = get_bits(gb, 4);

    flag = get_bits1(gb);

    for (i = 0; i < 8; i++) {

        ret = hq_decode_block(c, gb, c->block[i], qgroup, i >= 4, 0);

        if (ret < 0)

            return ret;

    }

    put_blocks(c, pic, 0, x,      y, flag, c->block[0], c->block[2]);

    put_blocks(c, pic, 0, x + 8,  y, flag, c->block[1], c->block[3]);

    put_blocks(c, pic, 2, x >> 1, y, flag, c->block[4], c->block[5]);

    put_blocks(c, pic, 1, x >> 1, y, flag, c->block[6], c->block[7]);

    return 0;

}

static int hq_decode_frame(HQContext *ctx, AVFrame *pic, GetByteContext *gbc,

                           int prof_num, size_t data_size)

{

    const HQProfile *profile;

    GetBitContext gb;

    const uint8_t *perm, *src = gbc->buffer;

    uint32_t slice_off[21];

    int slice, start_off, next_off, i, ret;

    if ((unsigned)prof_num >= NUM_HQ_PROFILES) {

        profile = &hq_profile[0];

        avpriv_request_sample(ctx->avctx, "HQ Profile %d", prof_num);

    } else {

        profile = &hq_profile[prof_num];

        av_log(ctx->avctx, AV_LOG_VERBOSE, "HQ Profile %d\n", prof_num);

    }

    if (bytestream2_get_bytes_left(gbc) < 3 * (profile->num_slices + 1))

        return AVERROR_INVALIDDATA;

    ctx->avctx->coded_width         = FFALIGN(profile->width,  16);

    ctx->avctx->coded_height        = FFALIGN(profile->height, 16);

    ctx->avctx->width               = profile->width;

    ctx->avctx->height              = profile->height;

    ctx->avctx->bits_per_raw_sample = 8;

    ctx->avctx->pix_fmt             = AV_PIX_FMT_YUV422P;

    ret = ff_get_buffer(ctx->avctx, pic, 0);

    if (ret < 0)

        return ret;

    /* Offsets are stored from CUV position, so adjust them accordingly. */

    for (i = 0; i < profile->num_slices + 1; i++)

        slice_off[i] = bytestream2_get_be24u(gbc) - 4;

    next_off = 0;

    for (slice = 0; slice < profile->num_slices; slice++) {

        start_off = next_off;

        next_off  = profile->tab_h * (slice + 1) / profile->num_slices;

        perm = profile->perm_tab + start_off * profile->tab_w * 2;

        if (slice_off[slice] < (profile->num_slices + 1) * 3 ||

            slice_off[slice] >= slice_off[slice + 1] ||

            slice_off[slice + 1] > data_size) {

            av_log(ctx->avctx, AV_LOG_ERROR,

                   "Invalid slice size %"SIZE_SPECIFIER".\n", data_size);

            break;

        }

        init_get_bits(&gb, src + slice_off[slice],

                      (slice_off[slice + 1] - slice_off[slice]) * 8);

        for (i = 0; i < (next_off - start_off) * profile->tab_w; i++) {

            ret = hq_decode_mb(ctx, pic, &gb, perm[0] * 16, perm[1] * 16);

            if (ret < 0) {

                av_log(ctx->avctx, AV_LOG_ERROR,

                       "Error decoding macroblock %d at slice %d.\n", i, slice);

                return ret;

            }

            perm += 2;

        }

    }

    return 0;

}

static int hqa_decode_mb(HQContext *c, AVFrame *pic, int qgroup,

                         GetBitContext *gb, int x, int y)

{

    int flag = 0;

    int i, ret;

    if (get_bits_left(gb) < 1)

        return AVERROR_INVALIDDATA;

    memset(c->block, 0, 12 * sizeof(c->block[0]));

    for (i = 0; i < 12; i++)

        c->block[i][0] = -128 * (1 << 6);

    int cbp = get_vlc2(gb, ff_hq_cbp_vlc, HQ_CBP_VLC_BITS, 1);

    if (cbp) {

        flag = get_bits1(gb);

        if (cbp & 0x3)

            cbp |= 0x500;

        if (cbp & 0xC)

            cbp |= 0xA00;

        for (i = 0; i < 12; i++) {

            if (!(cbp & (1 << i)))

                continue;

            ret = hq_decode_block(c, gb, c->block[i], qgroup, i >= 8, 1);

            if (ret < 0)

                return ret;

        }

    }

    put_blocks(c, pic, 3, x,      y, flag, c->block[ 0], c->block[ 2]);

    put_blocks(c, pic, 3, x + 8,  y, flag, c->block[ 1], c->block[ 3]);

    put_blocks(c, pic, 0, x,      y, flag, c->block[ 4], c->block[ 6]);

    put_blocks(c, pic, 0, x + 8,  y, flag, c->block[ 5], c->block[ 7]);

    put_blocks(c, pic, 2, x >> 1, y, flag, c->block[ 8], c->block[ 9]);

    put_blocks(c, pic, 1, x >> 1, y, flag, c->block[10], c->block[11]);

    return 0;

}

static int hqa_decode_slice(HQContext *ctx, AVFrame *pic, GetBitContext *gb,

                            int quant, int slice_no, int w, int h)

{

    int i, j, off;

    int ret;

    for (i = 0; i < h; i += 16) {

        off = (slice_no * 16 + i * 3) & 0x70;

        for (j = off; j < w; j += 128) {

            ret = hqa_decode_mb(ctx, pic, quant, gb, j, i);

            if (ret < 0) {

                av_log(ctx->avctx, AV_LOG_ERROR,

                       "Error decoding macroblock at %dx%d.\n", i, j);

                return ret;

            }

        }

    }

    return 0;

}

static int hqa_decode_frame(HQContext *ctx, AVFrame *pic, GetByteContext *gbc, size_t data_size)

{

    GetBitContext gb;

    const int num_slices = 8;

    uint32_t slice_off[9];

    int i, slice, ret;

    const uint8_t *src = gbc->buffer;

    if (bytestream2_get_bytes_left(gbc) < 8 + 4*(num_slices + 1))

        return AVERROR_INVALIDDATA;

    int width  = bytestream2_get_be16u(gbc);

    int height = bytestream2_get_be16u(gbc);

    ret = ff_set_dimensions(ctx->avctx, width, height);

    if (ret < 0)

        return ret;

    ctx->avctx->coded_width         = FFALIGN(width,  16);

    ctx->avctx->coded_height        = FFALIGN(height, 16);

    ctx->avctx->bits_per_raw_sample = 8;

    ctx->avctx->pix_fmt             = AV_PIX_FMT_YUVA422P;

    av_log(ctx->avctx, AV_LOG_VERBOSE, "HQA Profile\n");

    int quant = bytestream2_get_byteu(gbc);

    bytestream2_skipu(gbc, 3);

    if (quant >= NUM_HQ_QUANTS) {

        av_log(ctx->avctx, AV_LOG_ERROR,

               "Invalid quantization matrix %d.\n", quant);

        return AVERROR_INVALIDDATA;

    }

    ret = ff_get_buffer(ctx->avctx, pic, 0);

    if (ret < 0)

        return ret;

    /* Offsets are stored from HQA1 position, so adjust them accordingly. */

    for (i = 0; i < num_slices + 1; i++)

        slice_off[i] = bytestream2_get_be32u(gbc) - 4;

    for (slice = 0; slice < num_slices; slice++) {

        if (slice_off[slice] < (num_slices + 1) * 3 ||

            slice_off[slice] >= slice_off[slice + 1] ||

            slice_off[slice + 1] > data_size) {

            av_log(ctx->avctx, AV_LOG_ERROR,

                   "Invalid slice size %"SIZE_SPECIFIER".\n", data_size);

            break;

        }

        init_get_bits(&gb, src + slice_off[slice],

                      (slice_off[slice + 1] - slice_off[slice]) * 8);

        ret = hqa_decode_slice(ctx, pic, &gb, quant, slice, width, height);

        if (ret < 0)

            return ret;

    }

    return 0;

}

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

                               int *got_frame, AVPacket *avpkt)

{

    HQContext *ctx = avctx->priv_data;

    GetByteContext gbc0, *const gbc = &gbc0;

    unsigned int data_size;

    int ret;

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

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

        return AVERROR_INVALIDDATA;

    }

    bytestream2_init(gbc, avpkt->data, avpkt->size);

    uint32_t info_tag = bytestream2_peek_le32u(gbc);

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

        bytestream2_skipu(gbc, 4);

        int info_size = bytestream2_get_le32u(gbc);

        if (info_size < 0 || bytestream2_get_bytes_left(gbc) < info_size) {

            av_log(avctx, AV_LOG_ERROR, "Invalid INFO size (%d).\n", info_size);

            return AVERROR_INVALIDDATA;

        }

        ff_canopus_parse_info_tag(avctx, gbc->buffer, info_size);

        bytestream2_skipu(gbc, info_size);

    }

    data_size = bytestream2_get_bytes_left(gbc);

    if (data_size < 4) {

        av_log(avctx, AV_LOG_ERROR, "Frame is too small (%d).\n", data_size);

        return AVERROR_INVALIDDATA;

    }

    /* HQ defines dimensions and number of slices, and thus slice traversal

     * order. HQA has no size constraint and a fixed number of slices, so it

     * needs a separate scheme for it. */

    unsigned tag = bytestream2_get_le32u(gbc);

    if ((tag & 0x00FFFFFF) == (MKTAG('U', 'V', 'C', ' ') & 0x00FFFFFF)) {

        ret = hq_decode_frame(ctx, pic, gbc, tag >> 24, data_size);

    } else if (tag == MKTAG('H', 'Q', 'A', '1')) {

        ret = hqa_decode_frame(ctx, pic, gbc, data_size);

    } else {

        av_log(avctx, AV_LOG_ERROR, "Not a HQ/HQA frame.\n");

        return AVERROR_INVALIDDATA;

    }

    if (ret < 0) {

        av_log(avctx, AV_LOG_ERROR, "Error decoding frame.\n");

        return ret;

    }

    *got_frame = 1;

    return avpkt->size;

}

static av_cold void hq_init_static(void)

{

    VLC_INIT_STATIC_TABLE_FROM_LENGTHS(hq_ac_rvlc, 9, NUM_HQ_AC_ENTRIES,

                                       hq_ac_lens, 1, hq_ac_sym, 2, 2, 0, 0);

    for (size_t i = 0; i < FF_ARRAY_ELEMS(hq_ac_rvlc); ++i) {

        int len = hq_ac_rvlc[i].len;

        int sym = (int16_t)hq_ac_rvlc[i].sym, level = sym;

        // The invalid code has been remapped to HQ_AC_INVALID_RUN,

        // so the VLC is complete.

        av_assert1(len != 0);

        if (len > 0) {

            level = sym >> 7;

            hq_ac_rvlc[i].run = sym & 0x7F;

        }

        hq_ac_rvlc[i].len8  = len;

        hq_ac_rvlc[i].level = level;

    }

    for (size_t i = 0; i < FF_ARRAY_ELEMS(hq_quants); ++i) {

        for (size_t j = 0; j < FF_ARRAY_ELEMS(hq_quants[0]); ++j) {

            for (size_t k = 0; k < FF_ARRAY_ELEMS(hq_quants[0][0]); ++k)

                hq_quants[i][j][k] = qmats[hq_quant_map[i][j][k]];

        }

    }

}

static av_cold int hq_hqa_decode_init(AVCodecContext *avctx)

{

    static AVOnce init_static_once = AV_ONCE_INIT;

    HQContext *ctx = avctx->priv_data;

    ctx->avctx = avctx;

    ff_hqdsp_init(&ctx->hqhqadsp);

    ff_thread_once(&init_static_once, hq_init_static);

    return 0;

}

const FFCodec ff_hq_hqa_decoder = {

    .p.name         = "hq_hqa",

    CODEC_LONG_NAME("Canopus HQ/HQA"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_HQ_HQA,

    .priv_data_size = sizeof(HQContext),

    .init           = hq_hqa_decode_init,

    FF_CODEC_DECODE_CB(hq_hqa_decode_frame),

    .p.capabilities = AV_CODEC_CAP_DR1,

};