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ffmpeg / libavcodec / targaenc.c @ 72415b2a

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/*
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 * Targa (.tga) image encoder
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 * Copyright (c) 2007 Bobby Bingham
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "libavutil/intreadwrite.h"
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#include "avcodec.h"
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#include "rle.h"
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typedef struct TargaContext {
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    AVFrame picture;
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} TargaContext;
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/**
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 * RLE compress the image, with maximum size of out_size
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 * @param outbuf Output buffer
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 * @param out_size Maximum output size
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 * @param pic Image to compress
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 * @param bpp Bytes per pixel
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 * @param w Image width
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 * @param h Image height
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 * @return Size of output in bytes, or -1 if larger than out_size
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 */
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static int targa_encode_rle(uint8_t *outbuf, int out_size, AVFrame *pic,
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                            int bpp, int w, int h)
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{
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    int y,ret;
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    uint8_t *out;
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    out = outbuf;
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    for(y = 0; y < h; y ++) {
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        ret = ff_rle_encode(out, out_size, pic->data[0] + pic->linesize[0] * y, bpp, w, 0x7f, 0, -1, 0);
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        if(ret == -1){
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            return -1;
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        }
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        out+= ret;
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        out_size -= ret;
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    }
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    return out - outbuf;
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}
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static int targa_encode_normal(uint8_t *outbuf, AVFrame *pic, int bpp, int w, int h)
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{
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    int i, n = bpp * w;
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    uint8_t *out = outbuf;
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    uint8_t *ptr = pic->data[0];
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    for(i=0; i < h; i++) {
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        memcpy(out, ptr, n);
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        out += n;
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        ptr += pic->linesize[0];
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    }
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    return out - outbuf;
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}
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static int targa_encode_frame(AVCodecContext *avctx,
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                              unsigned char *outbuf,
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                              int buf_size, void *data){
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    AVFrame *p = data;
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    int bpp, picsize, datasize = -1;
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    uint8_t *out;
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    if(avctx->width > 0xffff || avctx->height > 0xffff) {
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        av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n");
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        return -1;
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    }
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    picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
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    if(buf_size < picsize + 45) {
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        av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
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        return -1;
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    }
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    p->pict_type= FF_I_TYPE;
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    p->key_frame= 1;
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    /* zero out the header and only set applicable fields */
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    memset(outbuf, 0, 12);
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    AV_WL16(outbuf+12, avctx->width);
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    AV_WL16(outbuf+14, avctx->height);
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    outbuf[17] = 0x20;           /* origin is top-left. no alpha */
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    /* TODO: support alpha channel */
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    switch(avctx->pix_fmt) {
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    case PIX_FMT_GRAY8:
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        outbuf[2] = 3;           /* uncompressed grayscale image */
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        outbuf[16] = 8;          /* bpp */
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        break;
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    case PIX_FMT_RGB555LE:
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        outbuf[2] = 2;           /* uncompresses true-color image */
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        outbuf[16] = 16;         /* bpp */
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        break;
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    case PIX_FMT_BGR24:
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        outbuf[2] = 2;           /* uncompressed true-color image */
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        outbuf[16] = 24;         /* bpp */
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        break;
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    default:
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        return -1;
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    }
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    bpp = outbuf[16] >> 3;
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    out = outbuf + 18;  /* skip past the header we just output */
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    /* try RLE compression */
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    if (avctx->coder_type != FF_CODER_TYPE_RAW)
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        datasize = targa_encode_rle(out, picsize, p, bpp, avctx->width, avctx->height);
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    /* if that worked well, mark the picture as RLE compressed */
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    if(datasize >= 0)
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        outbuf[2] |= 8;
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    /* if RLE didn't make it smaller, go back to no compression */
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    else datasize = targa_encode_normal(out, p, bpp, avctx->width, avctx->height);
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    out += datasize;
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    /* The standard recommends including this section, even if we don't use
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     * any of the features it affords. TODO: take advantage of the pixel
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     * aspect ratio and encoder ID fields available? */
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    memcpy(out, "\0\0\0\0\0\0\0\0TRUEVISION-XFILE.", 26);
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    return out + 26 - outbuf;
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}
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static av_cold int targa_encode_init(AVCodecContext *avctx)
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{
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    TargaContext *s = avctx->priv_data;
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    avcodec_get_frame_defaults(&s->picture);
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    s->picture.key_frame= 1;
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    avctx->coded_frame= &s->picture;
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    return 0;
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}
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AVCodec targa_encoder = {
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    .name = "targa",
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    .type = AVMEDIA_TYPE_VIDEO,
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    .id = CODEC_ID_TARGA,
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    .priv_data_size = sizeof(TargaContext),
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    .init = targa_encode_init,
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    .encode = targa_encode_frame,
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    .pix_fmts= (const enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_RGB555LE, PIX_FMT_GRAY8, PIX_FMT_NONE},
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    .long_name= NULL_IF_CONFIG_SMALL("Truevision Targa image"),
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};