Targa image decoder

Originally committed as revision 6640 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 244 insertions, 0 deletions

diff --git a/libavcodec/targa.c b/libavcodec/targa.c
new file mode 100644
index 0000000000..4f83bb61b2
--- /dev/null
+++ b/libavcodec/targa.c
@@ -0,0 +1,244 @@
+/*
+ * Targa (.tga) image decoder
+ * Copyright (c) 2006 Konstantin Shishkov
+ *
+ * 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 "avcodec.h"
+
+enum TargaCompr{
+    TGA_NODATA = 0, // no image data
+    TGA_PAL    = 1, // palettized
+    TGA_RGB    = 2, // true-color
+    TGA_BW     = 3, // black & white or grayscale
+    TGA_RLE    = 8, // flag pointing that data is RLE-coded
+};
+
+typedef struct TargaContext {
+    AVFrame picture;
+
+    int width, height;
+    int bpp;
+    int color_type;
+    int compression_type;
+} TargaContext;
+
+static void targa_decode_rle(AVCodecContext *avctx, TargaContext *s, uint8_t *src, uint8_t *dst, int w, int h, int stride, int bpp)
+{
+    int i, x, y;
+    int depth = (bpp + 1) >> 3;
+    int type, count;
+    int diff;
+
+    diff = stride - w * depth;
+    x = y = 0;
+    while(y < h){
+        type = *src++;
+        count = (type & 0x7F) + 1;
+        type &= 0x80;
+        if((x + count > w) && (x + count + 1 > (h - y) * w)){
+            av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds: position (%i,%i) size %i\n", x, y, count);
+            return;
+        }
+        for(i = 0; i < count; i++){
+            switch(depth){
+            case 1:
+                *dst = *src;
+                break;
+            case 2:
+                *((uint16_t*)dst) = LE_16(src);
+                break;
+            case 3:
+                dst[0] = src[0];
+                dst[1] = src[1];
+                dst[2] = src[2];
+                break;
+            }
+            dst += depth;
+            if(!type)
+                src += depth;
+
+            x++;
+            if(x == w){
+                x = 0;
+                y++;
+                dst += diff;
+            }
+        }
+        if(type)
+            src += depth;
+    }
+}
+
+static int decode_frame(AVCodecContext *avctx,
+                        void *data, int *data_size,
+                        uint8_t *buf, int buf_size)
+{
+    TargaContext * const s = avctx->priv_data;
+    AVFrame *picture = data;
+    AVFrame * const p= (AVFrame*)&s->picture;
+    uint8_t *dst;
+    int stride;
+    int idlen, pal, compr, x, y, w, h, bpp, flags;
+    int first_clr, colors, csize;
+
+    /* parse image header */
+    idlen = *buf++;
+    pal = *buf++;
+    compr = *buf++;
+    first_clr = LE_16(buf); buf += 2;
+    colors = LE_16(buf); buf += 2;
+    csize = *buf++;
+    x = LE_16(buf); buf += 2;
+    y = LE_16(buf); buf += 2;
+    w = LE_16(buf); buf += 2;
+    h = LE_16(buf); buf += 2;
+    bpp = *buf++;
+    flags = *buf++;
+    //skip identifier if any
+    buf += idlen;
+    s->bpp = bpp;
+    s->width = w;
+    s->height = h;
+    switch(s->bpp){
+    case 8:
+        avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? PIX_FMT_GRAY8 : PIX_FMT_PAL8;
+        break;
+    case 15:
+        avctx->pix_fmt = PIX_FMT_RGB555;
+        break;
+    case 16:
+        avctx->pix_fmt = PIX_FMT_RGB555;
+        break;
+    case 24:
+        avctx->pix_fmt = PIX_FMT_BGR24;
+        break;
+    default:
+        av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", avctx->bits_per_sample);
+        return -1;
+    }
+
+    if(s->picture.data[0])
+        avctx->release_buffer(avctx, &s->picture);
+
+    if(avcodec_check_dimensions(avctx, w, h))
+        return -1;
+    if(w != avctx->width || h != avctx->height)
+        avcodec_set_dimensions(avctx, w, h);
+    if(avctx->get_buffer(avctx, p) < 0){
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return -1;
+    }
+    if(flags & 0x20){
+        dst = p->data[0];
+        stride = p->linesize[0];
+    }else{ //image is upside-down
+        dst = p->data[0] + p->linesize[0] * (h - 1);
+        stride = -p->linesize[0];
+    }
+
+    if(avctx->pix_fmt == PIX_FMT_PAL8 && avctx->palctrl){
+        memcpy(p->data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
+        if(avctx->palctrl->palette_changed){
+            p->palette_has_changed = 1;
+            avctx->palctrl->palette_changed = 0;
+        }
+    }
+    if(colors){
+        if((colors + first_clr) > 256){
+            av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
+            return -1;
+        }
+        if(csize != 24){
+            av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
+            return -1;
+        }
+        if(avctx->pix_fmt != PIX_FMT_PAL8)//should not occur but skip palette anyway
+            buf += colors * ((csize + 1) >> 3);
+        else{
+            int r, g, b, t;
+            int32_t *pal = ((int32_t*)p->data[1]) + first_clr;
+            for(t = 0; t < colors; t++){
+                r = *buf++;
+                g = *buf++;
+                b = *buf++;
+                *pal++ = (b << 16) | (g << 8) | r;
+            }
+            p->palette_has_changed = 1;
+            avctx->palctrl->palette_changed = 0;
+        }
+    }
+    if((compr & (~TGA_RLE)) == TGA_NODATA)
+        memset(p->data[0], 0, p->linesize[0] * s->height);
+    else{
+        if(compr & TGA_RLE)
+            targa_decode_rle(avctx, s, buf, dst, avctx->width, avctx->height, stride, bpp);
+        else{
+            for(y = 0; y < s->height; y++){
+#ifdef WORDS_BIGENDIAN
+                if((s->bpp + 1) >> 3 == 2){
+                    uint16_t *dst16 = (uint16_t*)dst;
+                    for(x = 0; x < s->width; x++)
+                        dst16[x] = LE_16(buf + x * 2);
+                }else
+#endif
+                    memcpy(dst, buf, s->width * ((s->bpp + 1) >> 3));
+
+                dst += stride;
+                buf += s->width * ((s->bpp + 1) >> 3);
+            }
+        }
+    }
+
+    *picture= *(AVFrame*)&s->picture;
+    *data_size = sizeof(AVPicture);
+
+    return buf_size;
+}
+
+static int targa_init(AVCodecContext *avctx){
+    TargaContext *s = avctx->priv_data;
+
+    avcodec_get_frame_defaults((AVFrame*)&s->picture);
+    avctx->coded_frame= (AVFrame*)&s->picture;
+    s->picture.data[0] = NULL;
+
+    return 0;
+}
+
+static int targa_end(AVCodecContext *avctx){
+    TargaContext *s = avctx->priv_data;
+
+    if(s->picture.data[0])
+        avctx->release_buffer(avctx, &s->picture);
+
+    return 0;
+}
+
+AVCodec targa_decoder = {
+    "targa",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_TARGA,
+    sizeof(TargaContext),
+    targa_init,
+    NULL,
+    targa_end,
+    decode_frame,
+    0,
+    NULL
+};