PC Paintbrush PCX image decoder

Originally committed as revision 11321 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/Makefile

@@ -134,6 +134,7 @@ OBJS-$(CONFIG_NELLYMOSER_DECODER)      += nellymoserdec.o
 OBJS-$(CONFIG_NUV_DECODER)             += nuv.o rtjpeg.o
 OBJS-$(CONFIG_PAM_ENCODER)             += pnmenc.o pnm.o
 OBJS-$(CONFIG_PBM_ENCODER)             += pnmenc.o pnm.o
+OBJS-$(CONFIG_PCX_DECODER)             += pcx.o
 OBJS-$(CONFIG_PGM_ENCODER)             += pnmenc.o pnm.o
 OBJS-$(CONFIG_PGMYUV_ENCODER)          += pnmenc.o pnm.o
 OBJS-$(CONFIG_PNG_DECODER)             += png.o pngdec.o

libavcodec/allcodecs.c

@@ -118,6 +118,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER (NUV, nuv);
     REGISTER_ENCODER (PAM, pam);
     REGISTER_ENCODER (PBM, pbm);
+    REGISTER_DECODER (PCX, pcx);
     REGISTER_ENCODER (PGM, pgm);
     REGISTER_ENCODER (PGMYUV, pgmyuv);
     REGISTER_ENCDEC  (PNG, png);

libavcodec/avcodec.h

@@ -169,6 +169,7 @@ enum CodecID {
     CODEC_ID_VP6A,
     CODEC_ID_AMV,
     CODEC_ID_VB,
+    CODEC_ID_PCX,
 
     /* various PCM "codecs" */
     CODEC_ID_PCM_S16LE= 0x10000,

libavcodec/pcx.c

@@ -0,0 +1,246 @@
+/*
+ * PC Paintbrush PCX (.pcx) image decoder
+ * Copyright (c) 2007, 2008 Ivo van Poorten
+ *
+ * This decoder does not support CGA palettes. I am unable to find samples
+ * and Netpbm cannot generate them.
+ *
+ * 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"
+#include "bytestream.h"
+#include "bitstream.h"
+
+typedef struct PCXContext {
+    AVFrame picture;
+} PCXContext;
+
+static int pcx_init(AVCodecContext *avctx) {
+    PCXContext *s = avctx->priv_data;
+
+    avcodec_get_frame_defaults(&s->picture);
+    avctx->coded_frame= &s->picture;
+
+    return 0;
+}
+
+/**
+ * @return advanced src pointer
+ */
+static char *pcx_rle_decode(uint8_t *src, uint8_t *dst,
+                            unsigned int bytes_per_scanline) {
+    unsigned int i = 0;
+    unsigned char run, value;
+
+    while (i<bytes_per_scanline) {
+        run = 1;
+        value = *src++;
+        if (value >= 0xc0) {
+            run = value & 0x3f;
+            value = *src++;
+        }
+        while (i<bytes_per_scanline && run--)
+            dst[i++] = value;
+    }
+
+    return src;
+}
+
+static void pcx_palette(uint8_t **src, uint32_t *dst, unsigned int pallen) {
+    unsigned int i;
+
+    for (i=0; i<pallen; i++)
+        *dst++ = bytestream_get_be24(src);
+    memset(dst, 0, (256 - pallen) * sizeof(*dst));
+}
+
+static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
+                            uint8_t *buf, int buf_size) {
+    PCXContext * const s = avctx->priv_data;
+    AVFrame *picture = data;
+    AVFrame * const p = (AVFrame *)&s->picture;
+    int xmin, ymin, xmax, ymax;
+    unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
+                 bytes_per_scanline;
+    uint8_t *ptr, *bufstart = buf;
+
+    if (buf[0] != 0x0a || buf[1] > 5 || buf[1] == 1 || buf[2] != 1) {
+        av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
+        return -1;
+    }
+
+    xmin = AV_RL16(buf+ 4);
+    ymin = AV_RL16(buf+ 6);
+    xmax = AV_RL16(buf+ 8);
+    ymax = AV_RL16(buf+10);
+
+    if (xmax < xmin || ymax < ymin) {
+        av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
+        return -1;
+    }
+
+    w = xmax - xmin + 1;
+    h = ymax - ymin + 1;
+
+    bits_per_pixel     = buf[3];
+    bytes_per_line     = AV_RL16(buf+66);
+    nplanes            = buf[65];
+    bytes_per_scanline = nplanes * bytes_per_line;
+
+    if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) {
+        av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
+        return -1;
+    }
+
+    switch ((nplanes<<8) + bits_per_pixel) {
+        case 0x0308:
+            avctx->pix_fmt = PIX_FMT_RGB24;
+            break;
+        case 0x0108:
+        case 0x0104:
+        case 0x0102:
+        case 0x0101:
+        case 0x0401:
+        case 0x0301:
+        case 0x0201:
+            avctx->pix_fmt = PIX_FMT_PAL8;
+            break;
+        default:
+            av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
+            return -1;
+    }
+
+    buf += 128;
+
+    if (p->data[0])
+        avctx->release_buffer(avctx, p);
+
+    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;
+    }
+
+    p->pict_type = FF_I_TYPE;
+
+    ptr    = p->data[0];
+    stride = p->linesize[0];
+
+    if (nplanes == 3 && bits_per_pixel == 8) {
+        uint8_t scanline[bytes_per_scanline];
+
+        for (y=0; y<h; y++) {
+            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
+
+            for (x=0; x<w; x++) {
+                ptr[3*x  ] = scanline[x                    ];
+                ptr[3*x+1] = scanline[x+ bytes_per_line    ];
+                ptr[3*x+2] = scanline[x+(bytes_per_line<<1)];
+            }
+
+            ptr += stride;
+        }
+
+    } else if (nplanes == 1 && bits_per_pixel == 8) {
+        uint8_t scanline[bytes_per_scanline];
+        uint8_t *palstart = bufstart + buf_size - 769;
+
+        for (y=0; y<h; y++, ptr+=stride) {
+            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
+            memcpy(ptr, scanline, w);
+        }
+
+        if (buf != palstart) {
+            av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
+            buf = palstart;
+        }
+        if (*buf++ != 12) {
+            av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
+            return -1;
+        }
+
+    } else if (nplanes == 1) {   /* all packed formats, max. 16 colors */
+        uint8_t scanline[bytes_per_scanline];
+        GetBitContext s;
+
+        for (y=0; y<h; y++) {
+            init_get_bits(&s, scanline, bytes_per_scanline<<3);
+
+            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
+
+            for (x=0; x<w; x++)
+                ptr[x] = get_bits(&s, bits_per_pixel);
+            ptr += stride;
+        }
+
+    } else {    /* planar, 4, 8 or 16 colors */
+        uint8_t scanline[bytes_per_scanline];
+        int i;
+
+        for (y=0; y<h; y++) {
+            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
+
+            for (x=0; x<w; x++) {
+                int m = 0x80 >> (x&7), v = 0;
+                for (i=nplanes - 1; i>=0; i--) {
+                    v <<= 1;
+                    v  += !!(scanline[i*bytes_per_line + (x>>3)] & m);
+                }
+                ptr[x] = v;
+            }
+            ptr += stride;
+        }
+    }
+
+    if (nplanes == 1 && bits_per_pixel == 8) {
+        pcx_palette(&buf, (uint32_t *) p->data[1], 256);
+    } else if (bits_per_pixel < 8) {
+        uint8_t *palette = bufstart+16;
+        pcx_palette(&palette, (uint32_t *) p->data[1], 16);
+    }
+
+    *picture = s->picture;
+    *data_size = sizeof(AVFrame);
+
+    return buf - bufstart;
+}
+
+static int pcx_end(AVCodecContext *avctx) {
+    PCXContext *s = avctx->priv_data;
+
+    if(s->picture.data[0])
+        avctx->release_buffer(avctx, &s->picture);
+
+    return 0;
+}
+
+AVCodec pcx_decoder = {
+    "pcx",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_PCX,
+    sizeof(PCXContext),
+    pcx_init,
+    NULL,
+    pcx_end,
+    pcx_decode_frame,
+    0,
+    NULL
+};

libavformat/img2.c

@@ -57,6 +57,7 @@ static const IdStrMap img_tags[] = {
     { CODEC_ID_TIFF      , "tiff"},
     { CODEC_ID_SGI       , "sgi"},
     { CODEC_ID_PTX       , "ptx"},
+    { CODEC_ID_PCX       , "pcx"},
     {0, NULL}
 };