PeerStreamer

/*

 * 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 "libavutil/intreadwrite.h"

#include "avcodec.h"

#include "rle.h"

#include "targa.h"

typedef struct TargaContext {

    AVFrame picture;

} 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, 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, AVFrame *pic, int bpp, int w, int h)

{

    int i, n = bpp * w;

    uint8_t *out = outbuf;

    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,

                              unsigned char *outbuf,

                              int buf_size, void *data){

    AVFrame *p = data;

    int bpp, picsize, datasize = -1;

    uint8_t *out;

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

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

        return AVERROR(EINVAL);

    }

    picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);

    if(buf_size < picsize + 45) {

        av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");

        return AVERROR(EINVAL);

    }

    p->pict_type= AV_PICTURE_TYPE_I;

    p->key_frame= 1;

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

    memset(outbuf, 0, 12);

    AV_WL16(outbuf+12, avctx->width);

    AV_WL16(outbuf+14, avctx->height);

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

    outbuf[17] = 0x20 | (avctx->pix_fmt == PIX_FMT_BGRA ? 8 : 0);

    switch(avctx->pix_fmt) {

    case PIX_FMT_GRAY8:

        outbuf[2] = TGA_BW;      /* uncompressed grayscale image */

        outbuf[16] = 8;          /* bpp */

        break;

    case PIX_FMT_RGB555LE:

        outbuf[2] = TGA_RGB;     /* uncompresses true-color image */

        outbuf[16] = 16;         /* bpp */

        break;

    case PIX_FMT_BGR24:

        outbuf[2] = TGA_RGB;     /* uncompressed true-color image */

        outbuf[16] = 24;         /* bpp */

        break;

    case PIX_FMT_BGRA:

        outbuf[2] = TGA_RGB;     /* uncompressed true-color image */

        outbuf[16] = 32;         /* bpp */

        break;

    default:

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

               avcodec_get_pix_fmt_name(avctx->pix_fmt));

        return AVERROR(EINVAL);

    }

    bpp = outbuf[16] >> 3;

    out = outbuf + 18;  /* skip past the header we just output */

    /* try RLE compression */

    if (avctx->coder_type != FF_CODER_TYPE_RAW)

        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)

        outbuf[2] |= 8;

    /* 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);

    return out + 26 - outbuf;

}

static av_cold int targa_encode_init(AVCodecContext *avctx)

{

    TargaContext *s = avctx->priv_data;

    avcodec_get_frame_defaults(&s->picture);

    s->picture.key_frame= 1;

    avctx->coded_frame= &s->picture;

    return 0;

}

AVCodec ff_targa_encoder = {

    .name = "targa",

    .type = AVMEDIA_TYPE_VIDEO,

    .id = CODEC_ID_TARGA,

    .priv_data_size = sizeof(TargaContext),

    .init = targa_encode_init,

    .encode = targa_encode_frame,

    .pix_fmts= (const enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_BGRA, PIX_FMT_RGB555LE, PIX_FMT_GRAY8, PIX_FMT_NONE},

    .long_name= NULL_IF_CONFIG_SMALL("Truevision Targa image"),

};