[FFmpeg-devel] [PATCH] VBLE Decoder

Derek Buitenhuis derek.buitenhuis at gmail.com
Wed Nov 9 06:39:32 CET 2011


Add a decoder for the VBLE Lossless Codec, which
still has a cult following. Used to be popular
years ago on doom9.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
---
 Changelog              |    1 +
 doc/general.texi       |    1 +
 libavcodec/Makefile    |    1 +
 libavcodec/allcodecs.c |    1 +
 libavcodec/avcodec.h   |    1 +
 libavcodec/vble.c      |  245 ++++++++++++++++++++++++++++++++++++++++++++++++
 libavcodec/version.h   |    2 +-
 libavformat/riff.c     |    1 +
 8 files changed, 252 insertions(+), 1 deletions(-)
 create mode 100644 libavcodec/vble.c

diff --git a/Changelog b/Changelog
index 2e8d8af..7dd82ef 100644
--- a/Changelog
+++ b/Changelog
@@ -119,6 +119,7 @@ easier to use. The changes are:
 - Properly working defaults in libx264 wrapper, support for native presets.
 - Encrypted OMA files support
 - Discworld II BMV decoding support
+- VBLE Decoder
 
 
 version 0.8:
diff --git a/doc/general.texi b/doc/general.texi
index f026bfb..e530e11 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -532,6 +532,7 @@ following image formats are supported:
     @tab Codec used in DOS CD-ROM FlashBack game.
 @item Ut Video               @tab     @tab  X
 @item V210 Quicktime Uncompressed 4:2:2 10-bit     @tab  X  @tab  X
+ at item VBLE Lossless Codec    @tab     @tab  X
 @item VMware Screen Codec / VMware Video  @tab     @tab  X
     @tab Codec used in videos captured by VMware.
 @item Westwood Studios VQA (Vector Quantized Animation) video  @tab     @tab  X
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 2ffb5fd..68498a9 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -413,6 +413,7 @@ OBJS-$(CONFIG_V210_DECODER)            += v210dec.o
 OBJS-$(CONFIG_V210_ENCODER)            += v210enc.o
 OBJS-$(CONFIG_V210X_DECODER)           += v210x.o
 OBJS-$(CONFIG_VB_DECODER)              += vb.o
+OBJS-$(CONFIG_VBLE_DECODER)            += vble.o
 OBJS-$(CONFIG_VC1_DECODER)             += vc1dec.o vc1.o vc1data.o vc1dsp.o \
                                           msmpeg4.o msmpeg4data.o           \
                                           intrax8.o intrax8dsp.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 61678a6..8e43427 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -215,6 +215,7 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC  (V210,  v210);
     REGISTER_DECODER (V210X, v210x);
     REGISTER_DECODER (VB, vb);
+    REGISTER_DECODER (VBLE, vble);
     REGISTER_DECODER (VC1, vc1);
     REGISTER_DECODER (VC1_CRYSTALHD, vc1_crystalhd);
     REGISTER_DECODER (VC1_VDPAU, vc1_vdpau);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 07377c8..761a5f8 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -224,6 +224,7 @@ enum CodecID {
     CODEC_ID_UTVIDEO = 0x800,
 
     CODEC_ID_G2M        = MKBETAG( 0 ,'G','2','M'),
+    CODEC_ID_VBLE,
 
     /* various PCM "codecs" */
     CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
diff --git a/libavcodec/vble.c b/libavcodec/vble.c
new file mode 100644
index 0000000..c442c68
--- /dev/null
+++ b/libavcodec/vble.c
@@ -0,0 +1,245 @@
+/*
+ * VBLE Decoder
+ * Copyright (c) 2011 Derek Buitenhuis
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * VBLE Decoder
+ */
+
+/* Little endian bitstream */
+#define ALT_BITSTREAM_READER_LE
+
+#include "avcodec.h"
+#include "get_bits.h"
+
+typedef struct {
+    AVCodecContext *avctx;
+    
+    int size;
+    uint8_t *len;
+    uint32_t *val;
+} VBLEContext;
+
+static uint8_t vble_bitscan(GetBitContext *gb)
+{
+    uint32_t src = get_bits_long(gb, 32);
+
+    skip_bits_long(gb, -32);
+
+    for(int i = 0; i < 32; i++) {
+        if(src & (1 << i)) {
+            skip_bits_long(gb, i + 1);
+            return i;
+        }
+    }
+
+    return -1;
+}
+
+static void vble_unpack(VBLEContext *ctx, GetBitContext *gb)
+{
+    uint8_t *lengths = ctx->len;
+    int sum;
+
+    /* Read all the lengths in first */
+    for (int i = 0; i < ctx->size * 4; i++)
+        lengths[i] = vble_bitscan(gb);
+
+    /* Pixels are encoded in groups of 4 */
+    for (int i = 0; i < ctx->size; i++) {
+        lengths = ctx->len + i * 4;
+
+        sum = lengths[0] + lengths[1] + lengths[2] + lengths[3];
+
+        if(sum != 0)
+            ctx->val[i] = get_bits_long(gb, sum);
+        else
+            ctx->val[i] = 0;
+    }
+}
+
+static void vble_decode(VBLEContext *ctx)
+{
+    AVFrame *pic = ctx->avctx->coded_frame;
+    uint8_t *out;
+    uint8_t *lengths;
+    uint8_t pix, len_sum;
+    int pos;
+    int h = ctx->avctx->height;
+
+    for (int i = 0; i < ctx->size; i++) {
+        len_sum = 0;
+        lengths = ctx->len + i * 4;
+
+        for (int p = 0; p < 4; p++) {
+            pos = i * 4 + p; 
+
+            if (pos < pic->linesize[0] * h) {
+                /* Y */
+                out = pic->data[0];
+            }
+            else if (pos < pic->linesize[0] * h + pic->linesize[1] * h / 2) {
+                /* U */
+                out = pic->data[1];
+                pos -= pic->linesize[0] * h;
+            }
+            else {
+                /* V */
+                out = pic->data[2];
+                pos -= pic->linesize[0] * h + pic->linesize[1] * h / 2;
+            }
+
+            pix = (uint8_t)(ctx->val[i] >> len_sum);
+            pix &= (1 << (lengths[p])) - 1;
+            pix += (1 << (lengths[p])) - 1;
+
+            out[pos] = pix & 1 ? 255 - (pix >> 1) : pix >> 1;
+
+            len_sum += lengths[p];
+        }
+    }
+}
+
+static void vble_median_restore(uint8_t *plane, int width, int height)
+{
+    uint8_t *dst = plane;
+    uint8_t a, b, c;
+
+    for(int i = 1; i < width; i++)
+        dst[i] += dst[i - 1];
+
+    dst += width;
+
+    for(int i = 1; i < height; i++) { 
+        for(int j = 1; j < width; j++) {
+            a = dst[j - 1];
+            b = dst[j - width];
+            c = a + b - dst[j - 1 - width];
+            dst[j] += mid_pred(a, b, c);
+        }
+        dst += width;
+    }
+}
+
+static int vble_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
+                             AVPacket *avpkt)
+{
+    VBLEContext *ctx = avctx->priv_data;
+    AVFrame *pic = avctx->coded_frame;
+    GetBitContext gb;
+    const uint8_t *src = avpkt->data;
+    int version;
+    int w = avctx->width, h = avctx->height;
+
+    /* Clear buffer if need be */
+    if(pic->data[0])
+        avctx->release_buffer(avctx, pic);
+
+    /* Allocate buffer */
+    if(avctx->get_buffer(avctx, pic) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");
+        return -1;
+    }
+    
+    /* Set flags */
+    pic->reference = 0;
+    pic->key_frame = 1;
+    pic->pict_type = FF_I_TYPE;
+    
+    /* Codec is YV12-only */
+    pic->linesize[0] = w;
+    pic->linesize[1] = pic->linesize[2] = w / 2;
+
+    /* Version should always be 1 */
+    version = AV_RL32(src);
+    av_log(avctx, AV_LOG_DEBUG, "Version: %d\n", version);
+
+    if (version != 1) {
+        av_log(avctx, AV_LOG_ERROR, "Unsupported VBLE Version: %d\n", version);
+        return -1;
+    }
+    
+    /* Move past version */
+    src += 4;
+
+    init_get_bits(&gb, src, (avpkt->size - 4) * 8);
+
+    /* Unpack and decode */
+    vble_unpack(ctx, &gb);
+    vble_decode(ctx);
+
+    /* Restore planes. Should be almost identical to Huffyuv's. */
+    vble_median_restore(pic->data[0], pic->linesize[0], h);
+    vble_median_restore(pic->data[1], pic->linesize[1], h / 2);
+    vble_median_restore(pic->data[2], pic->linesize[2], h / 2);
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame *)data = *pic;
+
+    return avpkt->size;
+}
+
+static av_cold int vble_decode_init(AVCodecContext *avctx)
+{
+    VBLEContext *ctx = avctx->priv_data;
+
+    ctx->avctx = avctx;
+    
+    /* Number of samples divided by 4 */
+    ctx->size = (avctx->width * avctx->height * 3) / 8;
+
+    ctx->len = (uint8_t *)av_malloc(ctx->size * 4 * sizeof(uint8_t));
+    ctx->val = (uint32_t *)av_malloc(ctx->size * sizeof(uint32_t));
+
+    avctx->pix_fmt = PIX_FMT_YUV420P;
+    avctx->bits_per_raw_sample = 8;
+    avctx->coded_frame = avcodec_alloc_frame();
+
+    return 0;
+}
+
+static av_cold int vble_decode_close(AVCodecContext *avctx)
+{
+    VBLEContext *ctx = avctx->priv_data;
+    AVFrame *pic = avctx->coded_frame;
+
+    if(pic->data[0])
+        avctx->release_buffer(avctx, pic);
+
+    av_freep(&pic);
+    av_freep(&ctx->len);
+    av_freep(&ctx->val);
+
+    return 0;
+}
+
+AVCodec ff_vble_decoder = {
+    .name           = "vble",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_VBLE,
+    .priv_data_size = sizeof(VBLEContext),
+    .init           = vble_decode_init,
+    .close          = vble_decode_close,
+    .decode         = vble_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("VBLE Video Codec"),
+};
+
diff --git a/libavcodec/version.h b/libavcodec/version.h
index b09a9c5..9e82731 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -21,7 +21,7 @@
 #define AVCODEC_VERSION_H
 
 #define LIBAVCODEC_VERSION_MAJOR 53
-#define LIBAVCODEC_VERSION_MINOR 29
+#define LIBAVCODEC_VERSION_MINOR 30
 #define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
diff --git a/libavformat/riff.c b/libavformat/riff.c
index aea6eba..3acf80b 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -285,6 +285,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { CODEC_ID_UTVIDEO,      MKTAG('U', 'L', 'R', 'G') },
     { CODEC_ID_UTVIDEO,      MKTAG('U', 'L', 'Y', '0') },
     { CODEC_ID_UTVIDEO,      MKTAG('U', 'L', 'Y', '2') },
+    { CODEC_ID_VBLE,         MKTAG('V', 'B', 'L', 'E') },
     { CODEC_ID_NONE,         0 }
 };
 
-- 
1.7.7.1



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