PCX encoder that handles 1-, 8-, and 24-bpp pixfmts.

Patch by Daniel Verkamp, daniel drv nu

Originally committed as revision 18077 to svn://svn.ffmpeg.org/ffmpeg/trunk

Changelog

@@ -5,6 +5,7 @@ version <next>:
 - deprecated old scaler removed
 - VQF demuxer
 - Alpha channel scaler
+- PCX encoder
 
 
 

Makefile

@@ -224,6 +224,7 @@ LAVF_TESTS = $(addprefix regtest-,              \
         voc                                     \
         ogg                                     \
         pixfmt                                  \
+        pcx                                     \
     )
 
 REGFILES = $(addprefix tests/data/,$(addsuffix .$(1),$(2:regtest-%=%)))

doc/general.texi

@@ -251,7 +251,7 @@ following image formats are supported:
     @tab PAM is a PNM extension with alpha support.
 @item PBM          @tab X @tab X
     @tab Portable BitMap image
-@item PCX          @tab   @tab X
+@item PCX          @tab X @tab X
     @tab PC Paintbrush
 @item PGM          @tab X @tab X
     @tab Portable GrayMap image

libavcodec/Makefile

@@ -159,6 +159,7 @@ 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-$(CONFIG_PCX_ENCODER)             += pcxenc.o
 OBJS-$(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

@@ -127,7 +127,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER (NUV, nuv);
     REGISTER_ENCODER (PAM, pam);
     REGISTER_ENCODER (PBM, pbm);
-    REGISTER_DECODER (PCX, pcx);
+    REGISTER_ENCDEC  (PCX, pcx);
     REGISTER_ENCODER (PGM, pgm);
     REGISTER_ENCODER (PGMYUV, pgmyuv);
     REGISTER_ENCDEC  (PNG, png);

libavcodec/pcxenc.c

+/*
+ * PC Paintbrush PCX (.pcx) image encoder
+ * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
+ *
+ * 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
+ */
+
+/**
+ * PCX image encoder
+ * @file libavcodec/pcxenc.c
+ * @author Daniel Verkamp
+ * @sa http://www.qzx.com/pc-gpe/pcx.txt
+ */
+
+#include "avcodec.h"
+#include "bytestream.h"
+
+typedef struct PCXContext {
+    AVFrame picture;
+} PCXContext;
+
+static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
+
+static av_cold int pcx_encode_init(AVCodecContext *avctx)
+{
+    PCXContext *s = avctx->priv_data;
+
+    avcodec_get_frame_defaults(&s->picture);
+    avctx->coded_frame = &s->picture;
+
+    return 0;
+}
+
+/**
+ * PCX run-length encoder
+ * @param dst output buffer
+ * @param dst_size size of output buffer
+ * @param src input buffer
+ * @param src_plane_size size of one plane of input buffer in bytes
+ * @param nplanes number of planes in input buffer
+ * @return number of bytes written to dst or -1 on error
+ * @bug will not work for nplanes != 1 && bpp != 8
+ */
+static int pcx_rle_encode(      uint8_t *dst, int dst_size,
+                          const uint8_t *src, int src_plane_size, int nplanes)
+{
+    int p;
+    const uint8_t *dst_start = dst;
+
+    // check worst-case upper bound on dst_size
+    if (dst_size < 2LL * src_plane_size * nplanes || src_plane_size <= 0)
+        return -1;
+
+    for (p = 0; p < nplanes; p++) {
+        int count = 1;
+        const uint8_t *src_plane = src + p;
+        const uint8_t *src_plane_end = src_plane + src_plane_size * nplanes;
+        uint8_t prev = *src_plane;
+        src_plane += nplanes;
+
+        for (; ; src_plane += nplanes) {
+            if (src_plane < src_plane_end && *src_plane == prev && count < 0x3F) {
+                // current byte is same as prev
+                ++count;
+            } else {
+                // output prev * count
+                if (count != 1 || prev >= 0xC0)
+                    *dst++ = 0xC0 | count;
+                *dst++ = prev;
+
+                if (src_plane == src_plane_end)
+                    break;
+
+                // start new run
+                count = 1;
+                prev = *src_plane;
+            }
+        }
+    }
+
+    return dst - dst_start;
+}
+
+static int pcx_encode_frame(AVCodecContext *avctx,
+                            unsigned char *buf, int buf_size, void *data)
+{
+    PCXContext *s = avctx->priv_data;
+    AVFrame *const pict = &s->picture;
+    const uint8_t *buf_start = buf;
+    const uint8_t *buf_end   = buf + buf_size;
+
+    int bpp, nplanes, i, y, line_bytes, written;
+    const uint32_t *pal = NULL;
+    const uint8_t *src;
+
+    *pict = *(AVFrame *)data;
+    pict->pict_type = FF_I_TYPE;
+    pict->key_frame = 1;
+
+    if (avctx->width > 65535 || avctx->height > 65535) {
+        av_log(avctx, AV_LOG_ERROR, "image dimensions do not fit in 16 bits\n");
+        return -1;
+    }
+
+    switch (avctx->pix_fmt) {
+    case PIX_FMT_RGB24:
+        bpp = 8;
+        nplanes = 3;
+        break;
+    case PIX_FMT_RGB8:
+    case PIX_FMT_BGR8:
+    case PIX_FMT_RGB4_BYTE:
+    case PIX_FMT_BGR4_BYTE:
+    case PIX_FMT_GRAY8:
+    case PIX_FMT_PAL8:
+        bpp = 8;
+        nplanes = 1;
+        pal = (uint32_t *)pict->data[1];
+        break;
+    case PIX_FMT_MONOBLACK:
+        bpp = 1;
+        nplanes = 1;
+        pal = monoblack_pal;
+        break;
+    default:
+        av_log(avctx, AV_LOG_ERROR, "unsupported pixfmt\n");
+        return -1;
+    }
+
+    line_bytes = (avctx->width * bpp + 7) >> 3;
+    line_bytes = (line_bytes + 1) & ~1;
+
+    bytestream_put_byte(&buf, 10);                  // manufacturer
+    bytestream_put_byte(&buf, 5);                   // version
+    bytestream_put_byte(&buf, 1);                   // encoding
+    bytestream_put_byte(&buf, bpp);                 // bits per pixel per plane
+    bytestream_put_le16(&buf, 0);                   // x min
+    bytestream_put_le16(&buf, 0);                   // y min
+    bytestream_put_le16(&buf, avctx->width - 1);    // x max
+    bytestream_put_le16(&buf, avctx->height - 1);   // y max
+    bytestream_put_le16(&buf, 0);                   // horizontal DPI
+    bytestream_put_le16(&buf, 0);                   // vertical DPI
+    for (i = 0; i < 16; i++)
+        bytestream_put_be24(&buf, pal ? pal[i] : 0);// palette (<= 16 color only)
+    bytestream_put_byte(&buf, 0);                   // reserved
+    bytestream_put_byte(&buf, nplanes);             // number of planes
+    bytestream_put_le16(&buf, line_bytes);          // scanline plane size in bytes
+
+    while (buf - buf_start < 128)
+        *buf++= 0;
+
+    src = pict->data[0];
+
+    for (y = 0; y < avctx->height; y++) {
+        if ((written = pcx_rle_encode(buf, buf_end - buf,
+                                      src, line_bytes, nplanes)) < 0) {
+            av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
+            return -1;
+        }
+        buf += written;
+        src += pict->linesize[0];
+    }
+
+    if (nplanes == 1 && bpp == 8) {
+        if (buf_end - buf < 257) {
+            av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
+            return -1;
+        }
+        bytestream_put_byte(&buf, 12);
+        for (i = 0; i < 256; i++) {
+            bytestream_put_be24(&buf, pal[i]);
+        }
+    }
+
+    return buf - buf_start;
+}
+
+AVCodec pcx_encoder = {
+    "pcx",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_PCX,
+    sizeof(PCXContext),
+    pcx_encode_init,
+    pcx_encode_frame,
+    NULL,
+    .pix_fmts = (enum PixelFormat[]){
+        PIX_FMT_RGB24,
+        PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8,
+        PIX_FMT_MONOBLACK,
+        PIX_FMT_NONE},
+    .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
+};

libavformat/img2.c

@@ -428,7 +428,7 @@ AVOutputFormat image2_muxer = {
     "image2",
     NULL_IF_CONFIG_SMALL("image2 sequence"),
     "",
-    "bmp,jpeg,jpg,ljpg,pam,pbm,pgm,pgmyuv,png,ppm,sgi,tif,tiff,jp2",
+    "bmp,jpeg,jpg,ljpg,pam,pbm,pcx,pgm,pgmyuv,png,ppm,sgi,tif,tiff,jp2",
     sizeof(VideoData),
     CODEC_ID_NONE,
     CODEC_ID_MJPEG,

tests/libav.regression.ref

@@ -138,3 +138,6 @@ ac2c17f1a27d928e8b82f21dbafdd715 *./tests/data/b-libav-yuv440p.yuv
 304128 ./tests/data/b-libav-yuv440p.yuv
 10c8507ad38d0ce5e8cd0f1dd49b0d26 *./tests/data/b-libav-yuvj440p.yuv
 304128 ./tests/data/b-libav-yuvj440p.yuv
+574fb8fe0b2fe8cc0b3ded8549c052d4 *./tests/data/b-libav02.pcx
+./tests/data/b-libav%02d.pcx CRC=0x6f775c0d
+363436 ./tests/data/b-libav02.pcx

tests/regression.sh

@@ -601,6 +601,10 @@ if [ -n "$do_jpg" ] ; then
 do_image_formats jpg "-flags +bitexact -dct fastint -idct simple -pix_fmt yuvj420p" "-f image2"
 fi
 
+if [ -n "$do_pcx" ] ; then
+do_image_formats pcx
+fi
+
 # audio only
 
 if [ -n "$do_wav" ] ; then