/*

 * Vidvox Hap decoder

 * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>

 * Copyright (C) 2015 Tom Butterworth <bangnoise@gmail.com>

 *

 * HapQA and HAPAlphaOnly added by Jokyo Images

 *

 * 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

 * Hap decoder

 *

 * Fourcc: Hap1, Hap5, HapY, HapA, HapM

 *

 * https://github.com/Vidvox/hap/blob/master/documentation/HapVideoDRAFT.md

 */

#include <stdint.h>

#include "libavutil/imgutils.h"

#include "libavutil/mem.h"

#include "avcodec.h"

#include "bytestream.h"

#include "codec_internal.h"

#include "hap.h"

#include "snappy.h"

#include "texturedsp.h"

#include "thread.h"

static int hap_parse_decode_instructions(HapContext *ctx, int size)

{

    GetByteContext *gbc = &ctx->gbc;

    int section_size;

    enum HapSectionType section_type;

    int is_first_table = 1, had_offsets = 0, had_compressors = 0, had_sizes = 0;

    int i, ret;

    while (size > 0) {

        int stream_remaining = bytestream2_get_bytes_left(gbc);

        ret = ff_hap_parse_section_header(gbc, &section_size, &section_type);

        if (ret != 0)

            return ret;

        size -= stream_remaining - bytestream2_get_bytes_left(gbc);

        switch (section_type) {

            case HAP_ST_COMPRESSOR_TABLE:

                ret = ff_hap_set_chunk_count(ctx, section_size, is_first_table);

                if (ret != 0)

                    return ret;

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

                    ctx->chunks[i].compressor = bytestream2_get_byte(gbc) << 4;

                }

                had_compressors = 1;

                is_first_table = 0;

                break;

            case HAP_ST_SIZE_TABLE:

                ret = ff_hap_set_chunk_count(ctx, section_size / 4, is_first_table);

                if (ret != 0)

                    return ret;

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

                    ctx->chunks[i].compressed_size = bytestream2_get_le32(gbc);

                }

                had_sizes = 1;

                is_first_table = 0;

                break;

            case HAP_ST_OFFSET_TABLE:

                ret = ff_hap_set_chunk_count(ctx, section_size / 4, is_first_table);

                if (ret != 0)

                    return ret;

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

                    ctx->chunks[i].compressed_offset = bytestream2_get_le32(gbc);

                }

                had_offsets = 1;

                is_first_table = 0;

                break;

            default:

                break;

        }

        size -= section_size;

    }

    if (!had_sizes || !had_compressors)

        return AVERROR_INVALIDDATA;

    /* The offsets table is optional. If not present than calculate offsets by

     * summing the sizes of preceding chunks. */

    if (!had_offsets) {

        size_t running_size = 0;

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

            ctx->chunks[i].compressed_offset = running_size;

            if (ctx->chunks[i].compressed_size > UINT32_MAX - running_size)

                return AVERROR_INVALIDDATA;

            running_size += ctx->chunks[i].compressed_size;

        }

    }

    return 0;

}

static int hap_can_use_tex_in_place(HapContext *ctx)

{

    int i;

    size_t running_offset = 0;

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

        if (ctx->chunks[i].compressed_offset != running_offset

            || ctx->chunks[i].compressor != HAP_COMP_NONE)

            return 0;

        running_offset += ctx->chunks[i].compressed_size;

    }

    return 1;

}

static int hap_parse_frame_header(AVCodecContext *avctx)

{

    HapContext *ctx = avctx->priv_data;

    GetByteContext *gbc = &ctx->gbc;

    int section_size;

    enum HapSectionType section_type;

    const char *compressorstr;

    int i, ret;

    ret = ff_hap_parse_section_header(gbc, &ctx->texture_section_size, &section_type);

    if (ret != 0)

        return ret;

    if ((avctx->codec_tag == MKTAG('H','a','p','1') && (section_type & 0x0F) != HAP_FMT_RGBDXT1) ||

        (avctx->codec_tag == MKTAG('H','a','p','5') && (section_type & 0x0F) != HAP_FMT_RGBADXT5) ||

        (avctx->codec_tag == MKTAG('H','a','p','Y') && (section_type & 0x0F) != HAP_FMT_YCOCGDXT5) ||

        (avctx->codec_tag == MKTAG('H','a','p','A') && (section_type & 0x0F) != HAP_FMT_RGTC1) ||

        ((avctx->codec_tag == MKTAG('H','a','p','M') && (section_type & 0x0F) != HAP_FMT_RGTC1) &&

                                                        (section_type & 0x0F) != HAP_FMT_YCOCGDXT5)) {

        av_log(avctx, AV_LOG_ERROR,

               "Invalid texture format %#04x.\n", section_type & 0x0F);

        return AVERROR_INVALIDDATA;

    }

    switch (section_type & 0xF0) {

        case HAP_COMP_NONE:

        case HAP_COMP_SNAPPY:

            ret = ff_hap_set_chunk_count(ctx, 1, 1);

            if (ret == 0) {

                ctx->chunks[0].compressor = section_type & 0xF0;

                ctx->chunks[0].compressed_offset = 0;

                ctx->chunks[0].compressed_size = ctx->texture_section_size;

            }

            if (ctx->chunks[0].compressor == HAP_COMP_NONE) {

                compressorstr = "none";

            } else {

                compressorstr = "snappy";

            }

            break;

        case HAP_COMP_COMPLEX:

            ret = ff_hap_parse_section_header(gbc, &section_size, &section_type);

            if (ret == 0 && section_type != HAP_ST_DECODE_INSTRUCTIONS)

                ret = AVERROR_INVALIDDATA;

            if (ret == 0)

                ret = hap_parse_decode_instructions(ctx, section_size);

            compressorstr = "complex";

            break;

        default:

            ret = AVERROR_INVALIDDATA;

            break;

    }

    if (ret != 0)

        return ret;

    /* Check the frame is valid and read the uncompressed chunk sizes */

    ctx->tex_size = 0;

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

        HapChunk *chunk = &ctx->chunks[i];

        /* Check the compressed buffer is valid */

        if (chunk->compressed_offset + (uint64_t)chunk->compressed_size > bytestream2_get_bytes_left(gbc))

            return AVERROR_INVALIDDATA;

        /* Chunks are unpacked sequentially, ctx->tex_size is the uncompressed

         * size thus far */

        chunk->uncompressed_offset = ctx->tex_size;

        /* Fill out uncompressed size */

        if (chunk->compressor == HAP_COMP_SNAPPY) {

            GetByteContext gbc_tmp;

            int64_t uncompressed_size;

            bytestream2_init(&gbc_tmp, gbc->buffer + chunk->compressed_offset,

                             chunk->compressed_size);

            uncompressed_size = ff_snappy_peek_uncompressed_length(&gbc_tmp);

            if (uncompressed_size < 0) {

                return uncompressed_size;

            }

            chunk->uncompressed_size = uncompressed_size;

        } else if (chunk->compressor == HAP_COMP_NONE) {

            chunk->uncompressed_size = chunk->compressed_size;

        } else {

            return AVERROR_INVALIDDATA;

        }

        ctx->tex_size += chunk->uncompressed_size;

    }

    av_log(avctx, AV_LOG_DEBUG, "%s compressor\n", compressorstr);

    return ret;

}

static int decompress_chunks_thread(AVCodecContext *avctx, void *arg,

                                    int chunk_nb, int thread_nb)

{

    HapContext *ctx = avctx->priv_data;

    HapChunk *chunk = &ctx->chunks[chunk_nb];

    GetByteContext gbc;

    uint8_t *dst = ctx->tex_buf + chunk->uncompressed_offset;

    bytestream2_init(&gbc, ctx->gbc.buffer + chunk->compressed_offset, chunk->compressed_size);

    if (chunk->compressor == HAP_COMP_SNAPPY) {

        int ret;

        int64_t uncompressed_size = ctx->tex_size;

        /* Uncompress the frame */

        ret = ff_snappy_uncompress(&gbc, dst, &uncompressed_size);

        if (ret < 0) {

             av_log(avctx, AV_LOG_ERROR, "Snappy uncompress error\n");

             return ret;

        }

    } else if (chunk->compressor == HAP_COMP_NONE) {

        bytestream2_get_buffer(&gbc, dst, chunk->compressed_size);

    }

    return 0;

}

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

                      int *got_frame, AVPacket *avpkt)

{

    HapContext *ctx = avctx->priv_data;

    int ret, i, t;

    int section_size;

    enum HapSectionType section_type;

    int start_texture_section = 0;

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

    /* check for multi texture header */

    if (ctx->texture_count == 2) {

        ret = ff_hap_parse_section_header(&ctx->gbc, &section_size, &section_type);

        if (ret != 0)

            return ret;

        if ((section_type & 0x0F) != 0x0D) {

            av_log(avctx, AV_LOG_ERROR, "Invalid section type in 2 textures mode %#04x.\n", section_type);

            return AVERROR_INVALIDDATA;

        }

        start_texture_section = 4;

    }

    /* Get the output frame ready to receive data */

    ret = ff_thread_get_buffer(avctx, frame, 0);

    if (ret < 0)

        return ret;

    for (t = 0; t < ctx->texture_count; t++) {

        bytestream2_seek(&ctx->gbc, start_texture_section, SEEK_SET);

        /* Check for section header */

        ret = hap_parse_frame_header(avctx);

        if (ret < 0)

            return ret;

        if (ctx->tex_size != (avctx->coded_width  / TEXTURE_BLOCK_W)

            *(avctx->coded_height / TEXTURE_BLOCK_H)

            *ctx->dec[t].tex_ratio) {

            av_log(avctx, AV_LOG_ERROR, "uncompressed size mismatches\n");

            return AVERROR_INVALIDDATA;

        }

        start_texture_section += ctx->texture_section_size + 4;

        /* Unpack the DXT texture */

        if (hap_can_use_tex_in_place(ctx)) {

            int tex_size;

            /* Only DXTC texture compression in a contiguous block */

            ctx->dec[t].tex_data.in = ctx->gbc.buffer;

            tex_size = FFMIN(ctx->texture_section_size, bytestream2_get_bytes_left(&ctx->gbc));

            if (tex_size < (avctx->coded_width  / TEXTURE_BLOCK_W)

                *(avctx->coded_height / TEXTURE_BLOCK_H)

                *ctx->dec[t].tex_ratio) {

                av_log(avctx, AV_LOG_ERROR, "Insufficient data\n");

                return AVERROR_INVALIDDATA;

            }

        } else {

            /* Perform the second-stage decompression */

            ret = av_reallocp(&ctx->tex_buf, ctx->tex_size);

            if (ret < 0)

                return ret;

            avctx->execute2(avctx, decompress_chunks_thread, NULL,

                            ctx->chunk_results, ctx->chunk_count);

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

                if (ctx->chunk_results[i] < 0)

                    return ctx->chunk_results[i];

            }

            ctx->dec[t].tex_data.in = ctx->tex_buf;

        }

        ctx->dec[t].frame_data.out = frame->data[0];

        ctx->dec[t].stride = frame->linesize[0];

        ctx->dec[t].width  = avctx->coded_width;

        ctx->dec[t].height = avctx->coded_height;

        ff_texturedsp_exec_decompress_threads(avctx, &ctx->dec[t]);

    }

    /* Frame is ready to be output */

    *got_frame = 1;

    return avpkt->size;

}

static av_cold int hap_init(AVCodecContext *avctx)

{

    HapContext *ctx = avctx->priv_data;

    TextureDSPContext dxtc;

    const char *texture_name;

    int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);

    if (ret < 0) {

        av_log(avctx, AV_LOG_ERROR, "Invalid video size %dx%d.\n",

               avctx->width, avctx->height);

        return ret;

    }

    /* Since codec is based on 4x4 blocks, size is aligned to 4 */

    avctx->coded_width  = FFALIGN(avctx->width,  TEXTURE_BLOCK_W);

    avctx->coded_height = FFALIGN(avctx->height, TEXTURE_BLOCK_H);

    ff_texturedsp_init(&dxtc);

    ctx->texture_count  = 1;

    ctx->dec[0].raw_ratio = 16;

    ctx->dec[0].slice_count = av_clip(avctx->thread_count, 1,

                                      avctx->coded_height / TEXTURE_BLOCK_H);

    switch (avctx->codec_tag) {

    case MKTAG('H','a','p','1'):

        texture_name = "DXT1";

        ctx->dec[0].tex_ratio = 8;

        ctx->dec[0].tex_funct = dxtc.dxt1_block;

        avctx->pix_fmt = AV_PIX_FMT_RGB0;

        break;

    case MKTAG('H','a','p','5'):

        texture_name = "DXT5";

        ctx->dec[0].tex_ratio = 16;

        ctx->dec[0].tex_funct = dxtc.dxt5_block;

        avctx->pix_fmt = AV_PIX_FMT_RGBA;

        break;

    case MKTAG('H','a','p','Y'):

        texture_name = "DXT5-YCoCg-scaled";

        ctx->dec[0].tex_ratio = 16;

        ctx->dec[0].tex_funct = dxtc.dxt5ys_block;

        avctx->pix_fmt = AV_PIX_FMT_RGB0;

        break;

    case MKTAG('H','a','p','A'):

        texture_name = "RGTC1";

        ctx->dec[0].tex_ratio = 8;

        ctx->dec[0].tex_funct = dxtc.rgtc1u_gray_block;

        ctx->dec[0].raw_ratio = 4;

        avctx->pix_fmt = AV_PIX_FMT_GRAY8;

        break;

    case MKTAG('H','a','p','M'):

        texture_name  = "DXT5-YCoCg-scaled / RGTC1";

        ctx->dec[0].tex_ratio = 16;

        ctx->dec[1].tex_ratio = 8;

        ctx->dec[0].tex_funct = dxtc.dxt5ys_block;

        ctx->dec[1].tex_funct = dxtc.rgtc1u_alpha_block;

        ctx->dec[1].raw_ratio = 16;

        ctx->dec[1].slice_count = ctx->dec[0].slice_count;

        avctx->pix_fmt = AV_PIX_FMT_RGBA;

        ctx->texture_count = 2;

        break;

    default:

        return AVERROR_DECODER_NOT_FOUND;

    }

    av_log(avctx, AV_LOG_DEBUG, "%s texture\n", texture_name);

    return 0;

}

static av_cold int hap_close(AVCodecContext *avctx)

{

    HapContext *ctx = avctx->priv_data;

    ff_hap_free_context(ctx);

    return 0;

}

const FFCodec ff_hap_decoder = {

    .p.name         = "hap",

    CODEC_LONG_NAME("Vidvox Hap"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_HAP,

    .init           = hap_init,

    FF_CODEC_DECODE_CB(hap_decode),

    .close          = hap_close,

    .priv_data_size = sizeof(HapContext),

    .p.capabilities = AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_SLICE_THREADS |

                      AV_CODEC_CAP_DR1,

    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,

    .codec_tags     = (const uint32_t []){

        MKTAG('H','a','p','1'),

        MKTAG('H','a','p','5'),

        MKTAG('H','a','p','Y'),

        MKTAG('H','a','p','A'),

        MKTAG('H','a','p','M'),

        FF_CODEC_TAGS_END,

    },

};