8BPS decoder

Originally committed as revision 2486 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 228 insertions, 0 deletions

diff --git a/libavcodec/8bps.c b/libavcodec/8bps.c
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+++ b/libavcodec/8bps.c
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+/*
+ * Quicktime Planar RGB (8BPS) Video Decoder
+ * Copyright (C) 2003 Roberto Togni
+ *
+ * This library 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 of the License, or (at your option) any later version.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+/**
+ * @file 8bps.c
+ * QT 8BPS Video Decoder by Roberto Togni <rtogni at bresciaonline dot it>
+ * For more information about the 8BPS format, visit:
+ *   http://www.pcisys.net/~melanson/codecs/
+ *
+ * Supports: PAL8 (RGB 8bpp, paletted)
+ *         : BGR24 (RGB 24bpp) (can also output it as RGBA32)
+ *         : RGBA32 (RGB 32bpp, 4th plane is probably alpha and it's ignored)
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "common.h"
+#include "avcodec.h"
+
+
+const enum PixelFormat pixfmt_rgb24[] = {PIX_FMT_BGR24, PIX_FMT_RGBA32, -1};
+
+/*
+ * Decoder context
+ */
+typedef struct EightBpsContext {
+
+	AVCodecContext *avctx;
+	AVFrame pic;
+
+	unsigned char planes;
+	unsigned char planemap[4];
+} EightBpsContext;
+
+
+/*
+ *
+ * Decode a frame
+ *
+ */
+static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
+{
+	EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;
+	unsigned char *encoded = (unsigned char *)buf;
+	unsigned char *pixptr;
+	unsigned int height = avctx->height; // Real image height
+	unsigned int dlen, p, row;
+	unsigned char *lp, *dp;
+	unsigned char count;
+	unsigned int px_inc;
+	unsigned int planes = c->planes;
+	unsigned char *planemap = c->planemap;
+  
+  
+	/* no supplementary picture */
+	if (buf_size == 0)
+		return 0;
+
+	if(c->pic.data[0])
+		avctx->release_buffer(avctx, &c->pic);
+
+	c->pic.reference = 0;
+	c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
+	if(avctx->get_buffer(avctx, &c->pic) < 0){
+		av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+		return -1;
+	}
+
+	/* Set data pointer after line lengths */
+	dp = encoded + planes * (height << 1);
+
+	/* Ignore alpha plane, don't know what to do with it */
+	if (planes == 4)
+		planes--;
+
+	px_inc = planes + (avctx->pix_fmt == PIX_FMT_RGBA32);
+
+	for (p = 0; p < planes; p++) {
+		/* Lines length pointer for this plane */
+		lp = encoded + p * (height << 1);
+
+		/* Decode a plane */
+		for(row = 0; row < height; row++) {
+			pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
+			dlen = be2me_16(*(unsigned short *)(lp+row*2));
+			/* Decode a row of this plane */
+			while(dlen > 0) {
+				if ((count = *dp++) <= 127) {
+					count++;
+					dlen -= count + 1;
+					while(count--) {
+						*pixptr = *dp++;
+						pixptr += px_inc;
+					}
+				} else {
+					count = 257 - count;
+					while(count--) {
+						*pixptr = *dp;
+						pixptr += px_inc;
+					}
+					dp++;
+					dlen -= 2;
+				}
+			}
+		}
+	}
+
+	if (avctx->palctrl) {
+		memcpy (c->pic.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
+		if (avctx->palctrl->palette_changed) {
+			c->pic.palette_has_changed = 1;
+			avctx->palctrl->palette_changed = 0;
+		} else
+			c->pic.palette_has_changed = 0;
+	}
+
+	*data_size = sizeof(AVFrame);
+	*(AVFrame*)data = c->pic;
+
+	/* always report that the buffer was completely consumed */
+	return buf_size;
+}
+
+
+/*
+ *
+ * Init 8BPS decoder
+ *
+ */
+static int decode_init(AVCodecContext *avctx)
+{
+	EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;
+
+	c->avctx = avctx;
+	avctx->has_b_frames = 0;
+
+	c->pic.data[0] = NULL;
+
+	switch (avctx->bits_per_sample) {
+		case 8:
+			avctx->pix_fmt = PIX_FMT_PAL8;
+			c->planes = 1;
+			c->planemap[0] = 0; // 1st plane is palette indexes
+			if (avctx->palctrl == NULL) {
+				av_log(avctx, AV_LOG_ERROR, "Error: PAL8 format but no palette from demuxer.\n");
+				return -1;
+			}
+			break;
+		case 24:
+			avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
+			c->planes = 3;
+			c->planemap[0] = 2; // 1st plane is red
+			c->planemap[1] = 1; // 2nd plane is green
+			c->planemap[2] = 0; // 3rd plane is blue
+			break;
+		case 32:
+			avctx->pix_fmt = PIX_FMT_RGBA32;
+			c->planes = 4;
+#ifdef WORDS_BIGENDIAN
+			c->planemap[0] = 1; // 1st plane is red
+			c->planemap[1] = 2; // 2nd plane is green
+			c->planemap[2] = 3; // 3rd plane is blue
+			c->planemap[3] = 0; // 4th plane is alpha???
+#else
+			c->planemap[0] = 2; // 1st plane is red
+			c->planemap[1] = 1; // 2nd plane is green
+			c->planemap[2] = 0; // 3rd plane is blue
+			c->planemap[3] = 3; // 4th plane is alpha???
+#endif
+			break;
+		default:
+			av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_sample);
+			return -1;
+	}
+
+  return 0;
+}
+
+
+
+
+/*
+ *
+ * Uninit 8BPS decoder
+ *
+ */
+static int decode_end(AVCodecContext *avctx)
+{
+	EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;
+
+	if (c->pic.data[0])
+		avctx->release_buffer(avctx, &c->pic);
+
+	return 0;
+}
+
+
+
+AVCodec eightbps_decoder = {
+	"8bps",
+	CODEC_TYPE_VIDEO,
+	CODEC_ID_8BPS,
+	sizeof(EightBpsContext),
+	decode_init,
+	NULL,
+	decode_end,
+	decode_frame,
+	CODEC_CAP_DR1,
+};