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

1 files changed, 206 insertions, 0 deletions

diff --git a/libavcodec/pcxenc.c b/libavcodec/pcxenc.c
new file mode 100644
index 0000000000..36f7d1d84c
--- /dev/null
+++ b/libavcodec/pcxenc.c
@@ -0,0 +1,206 @@
+/*
+ * 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"),
+};