[FFmpeg-devel] [PATCH] PCX encoder

Daniel Verkamp daniel
Sat Mar 14 21:09:54 CET 2009


On Sat, Mar 14, 2009 at 3:50 PM, Daniel Verkamp <daniel at drv.nu> wrote:
> Hi,
>
> Attached is a patch for a PCX image encoder that handles 1-, 8-, and
> 24-bpp pixfmts. ?1 and 8 bpp tested with pbrush from Win3.11, 24 bpp
> tested with IrfanView; if anyone has a version of PC Paintbrush that
> supports 24 bpp, please test, but I am fairly sure it is correct.
>
> Thanks,
> -- Daniel Verkamp
>

Silly last-minute change broke compilation - fixed patch attached.
-------------- next part --------------
>From 3eaf674c4bd72e21b88d4c01cf5f4586d1f0a392 Mon Sep 17 00:00:00 2001
From: Daniel Verkamp <daniel at drv.nu>
Date: Sat, 14 Mar 2009 14:41:56 -0500
Subject: [PATCH] Add PCX encoder

---
 Changelog              |    1 +
 doc/general.texi       |    2 +-
 libavcodec/Makefile    |    1 +
 libavcodec/allcodecs.c |    2 +-
 libavcodec/pcxenc.c    |  208 ++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 212 insertions(+), 2 deletions(-)
 create mode 100644 libavcodec/pcxenc.c

diff --git a/Changelog b/Changelog
index 7538ea6..0d2a16e 100644
--- a/Changelog
+++ b/Changelog
@@ -4,6 +4,7 @@ version <next>:
 - deprecated vhook subsystem removed
 - deprecated old scaler removed
 - VQF demuxer
+- PCX encoder
 
 
 
diff --git a/doc/general.texi b/doc/general.texi
index 143aef4..7e84a58 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -250,7 +250,7 @@ following image formats are supported:
     @tab PAM is a PNM extension with alpha support.
 @item PBM          @tab X @tab X
     @tab Portable BitMap image
- at item PCX          @tab   @tab X
+ at item PCX          @tab X @tab X
     @tab PC Paintbrush
 @item PGM          @tab X @tab X
     @tab Portable GrayMap image
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 13415fc..8175fc5 100644
--- a/libavcodec/Makefile
+++ b/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
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index b024e01..bc37401 100644
--- a/libavcodec/allcodecs.c
+++ b/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);
diff --git a/libavcodec/pcxenc.c b/libavcodec/pcxenc.c
new file mode 100644
index 0000000..e078ba8
--- /dev/null
+++ b/libavcodec/pcxenc.c
@@ -0,0 +1,208 @@
+/*
+ * 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_size size of input buffer
+ * @return number of bytes written to dst or -1 on error
+ */
+static int pcx_rle_encode(      uint8_t *dst, int dst_size,
+                          const uint8_t *src, int src_size)
+{
+    int i;
+    uint8_t prev = src[0];
+    int count = 1;
+    int dst_used = 0;
+
+    for (i = 1; i <= src_size; i++) {
+        if (i != src_size && src[i] == prev && count < 0x3F) {
+            // current byte is same as prev
+            ++count;
+        } else {
+            // output prev * count
+            if (count == 1 && prev < 0xC0) {
+                if (++dst_used > dst_size)
+                    return -1;
+                *dst++ = prev;
+            } else {
+                dst_used += 2;
+                if (dst_used > dst_size)
+                    return -1;
+                *dst++ = 0xC0 | count;
+                *dst++ = prev;
+            }
+
+            // get new prev
+            if (i != src_size) {
+                count = 1;
+                prev = src[i];
+            }
+        }
+    }
+
+    return dst_used;
+}
+
+static int pcx_encode_frame(AVCodecContext *avctx,
+                            unsigned char *buf, int buf_size, void *data)
+{
+    PCXContext *s = avctx->priv_data;
+    AVFrame *pict = data;
+    AVFrame *const p = &s->picture;
+    uint8_t const *bufstart = buf;
+
+    int bpp, nplanes, i, j, k, l, line_bytes, filler, written, src_line_size;
+    const uint32_t *pal = NULL;
+    const uint8_t *src;
+    uint8_t *plane;
+
+    *p = *pict;
+    p->pict_type = FF_I_TYPE;
+    p->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 *)p->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
+
+    filler = 128 - (buf - bufstart);
+    memset(buf, 0, filler);
+    buf += filler;
+
+    plane = av_mallocz(line_bytes);
+    src = p->data[0];
+    src_line_size = (avctx->width * nplanes * bpp + 7) >> 3;
+
+    for (i = 0; i < avctx->height; i++) {
+        for (j = 0; j < nplanes; j++) {
+            for (k = j, l = 0; k < src_line_size; k += nplanes, l++) {
+                plane[l] = src[k];
+            }
+            if ((written = pcx_rle_encode(buf, buf_size - (buf - bufstart),
+                                          plane, line_bytes)) < 0) {
+                av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
+                return -1;
+            }
+            buf += written;
+        }
+        src += p->linesize[0];
+    }
+
+    av_free(plane);
+
+    if (nplanes == 1 && bpp == 8) {
+        bytestream_put_byte(&buf, 12);
+        for (i = 0; i < 256; i++) {
+            bytestream_put_be24(&buf, pal[i]);
+        }
+    }
+
+    return buf - bufstart;
+}
+
+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"),
+};
-- 
1.6.2



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