/*

 * Targa (.tga) image encoder

 * Copyright (c) 2007 Bobby Bingham

 *

 * 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 <string.h>

#include "libavutil/avassert.h"

#include "libavutil/imgutils.h"

#include "libavutil/internal.h"

#include "libavutil/intreadwrite.h"

#include "libavutil/opt.h"

#include "libavutil/pixdesc.h"

#include "avcodec.h"

#include "codec_internal.h"

#include "encode.h"

#include "rle.h"

#include "targa.h"

typedef struct TargaContext {

    AVClass *class;

    int rle;

} TargaContext;

/**

 * RLE compress the image, with maximum size of out_size

 * @param outbuf Output buffer

 * @param out_size Maximum output size

 * @param pic Image to compress

 * @param bpp Bytes per pixel

 * @param w Image width

 * @param h Image height

 * @return Size of output in bytes, or -1 if larger than out_size

 */

static int targa_encode_rle(uint8_t *outbuf, int out_size, const AVFrame *pic,

                            int bpp, int w, int h)

{

    int y,ret;

    uint8_t *out;

    out = outbuf;

    for(y = 0; y < h; y ++) {

        ret = ff_rle_encode(out, out_size, pic->data[0] + pic->linesize[0] * y, bpp, w, 0x7f, 0, -1, 0);

        if(ret == -1){

            return -1;

        }

        out+= ret;

        out_size -= ret;

    }

    return out - outbuf;

}

static int targa_encode_normal(uint8_t *outbuf, const AVFrame *pic, int bpp, int w, int h)

{

    int i, n = bpp * w;

    uint8_t *out = outbuf;

    const uint8_t *ptr = pic->data[0];

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

        memcpy(out, ptr, n);

        out += n;

        ptr += pic->linesize[0];

    }

    return out - outbuf;

}

static int targa_encode_frame(AVCodecContext *avctx, AVPacket *pkt,

                              const AVFrame *p, int *got_packet)

{

    TargaContext *s = avctx->priv_data;

    int bpp, picsize, datasize = -1, ret, i;

    uint8_t *out;

    int maxpal = 32*32;

    picsize = av_image_get_buffer_size(avctx->pix_fmt,

                                       avctx->width, avctx->height, 1);

    if ((ret = ff_alloc_packet(avctx, pkt, picsize + 45 + maxpal)) < 0)

        return ret;

    /* zero out the header and only set applicable fields */

    memset(pkt->data, 0, 12);

    AV_WL16(pkt->data+12, avctx->width);

    AV_WL16(pkt->data+14, avctx->height);

    /* image descriptor byte: origin is always top-left, bits 0-3 specify alpha */

    pkt->data[17] = 0x20 | (avctx->pix_fmt == AV_PIX_FMT_BGRA ? 8 : 0);

    out = pkt->data + 18;  /* skip past the header we write */

    avctx->bits_per_coded_sample = av_get_bits_per_pixel(av_pix_fmt_desc_get(avctx->pix_fmt));

    switch(avctx->pix_fmt) {

    case AV_PIX_FMT_PAL8: {

        int pal_bpp = 24; /* Only write 32bit palette if there is transparency information */

        for (i = 0; i < 256; i++)

            if (AV_RN32(p->data[1] + 4 * i) >> 24 != 0xFF) {

                pal_bpp = 32;

                break;

            }

        pkt->data[1]  = 1;          /* palette present */

        pkt->data[2]  = TGA_PAL;    /* uncompressed palettised image */

        pkt->data[6]  = 1;          /* palette contains 256 entries */

        pkt->data[7]  = pal_bpp;    /* palette contains pal_bpp bit entries */

        pkt->data[16] = 8;          /* bpp */

        for (i = 0; i < 256; i++)

            if (pal_bpp == 32) {

                AV_WL32(pkt->data + 18 + 4 * i, *(uint32_t *)(p->data[1] + i * 4));

            } else {

            AV_WL24(pkt->data + 18 + 3 * i, *(uint32_t *)(p->data[1] + i * 4));

            }

        out += 32 * pal_bpp;        /* skip past the palette we just output */

        av_assert0(32 * pal_bpp <= maxpal);

        break;

        }

    case AV_PIX_FMT_GRAY8:

        pkt->data[2]  = TGA_BW;     /* uncompressed grayscale image */

        avctx->bits_per_coded_sample = 0x28;

        pkt->data[16] = 8;          /* bpp */

        break;

    case AV_PIX_FMT_RGB555LE:

        pkt->data[2]  = TGA_RGB;    /* uncompressed true-color image */

        avctx->bits_per_coded_sample =

        pkt->data[16] = 16;         /* bpp */

        break;

    case AV_PIX_FMT_BGR24:

        pkt->data[2]  = TGA_RGB;    /* uncompressed true-color image */

        pkt->data[16] = 24;         /* bpp */

        break;

    case AV_PIX_FMT_BGRA:

        pkt->data[2]  = TGA_RGB;    /* uncompressed true-color image */

        pkt->data[16] = 32;         /* bpp */

        break;

    default:

        av_log(avctx, AV_LOG_ERROR, "Pixel format '%s' not supported.\n",

               av_get_pix_fmt_name(avctx->pix_fmt));

        return AVERROR(EINVAL);

    }

    bpp = pkt->data[16] >> 3;

    /* try RLE compression */

    if (s->rle)

        datasize = targa_encode_rle(out, picsize, p, bpp, avctx->width, avctx->height);

    /* if that worked well, mark the picture as RLE compressed */

    if(datasize >= 0)

        pkt->data[2] |= TGA_RLE;

    /* if RLE didn't make it smaller, go back to no compression */

    else datasize = targa_encode_normal(out, p, bpp, avctx->width, avctx->height);

    out += datasize;

    /* The standard recommends including this section, even if we don't use

     * any of the features it affords. TODO: take advantage of the pixel

     * aspect ratio and encoder ID fields available? */

    memcpy(out, "\0\0\0\0\0\0\0\0TRUEVISION-XFILE.", 26);

    pkt->size   = out + 26 - pkt->data;

    *got_packet = 1;

    return 0;

}

static av_cold int targa_encode_init(AVCodecContext *avctx)

{

    if (avctx->width > 0xffff || avctx->height > 0xffff) {

        av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n");

        return AVERROR(EINVAL);

    }

    return 0;

}

#define OFFSET(x) offsetof(TargaContext, x)

#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM

static const AVOption options[] = {

    { "rle", "Use run-length compression", OFFSET(rle), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, VE },

    { NULL },

};

static const AVClass targa_class = {

    .class_name = "targa",

    .item_name  = av_default_item_name,

    .option     = options,

    .version    = LIBAVUTIL_VERSION_INT,

};

const FFCodec ff_targa_encoder = {

    .p.name         = "targa",

    CODEC_LONG_NAME("Truevision Targa image"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_TARGA,

    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,

    .priv_data_size = sizeof(TargaContext),

    .p.priv_class   = &targa_class,

    .init           = targa_encode_init,

    FF_CODEC_ENCODE_CB(targa_encode_frame),

    CODEC_PIXFMTS(AV_PIX_FMT_BGR24, AV_PIX_FMT_BGRA, AV_PIX_FMT_RGB555LE,

                  AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8),

};