@@ -74,6 +74,7 @@ version <next>:

 - Lagarith decoder

 - ffmpeg -copytb option added

 - IVF muxer added

+- Wing Commander IV movies decoder added

 version 0.6:

@@ -511,6 +511,8 @@ following image formats are supported:

     @tab not completely working

 @item Wing Commander III / Xan  @tab     @tab  X

     @tab Used in Wing Commander III .MVE files.

+@item Wing Commander IV / Xan  @tab     @tab  X

+    @tab Used in Wing Commander IV.

 @item Winnov WNV1            @tab     @tab  X

 @item WMV7                   @tab  X  @tab  X

 @item YAMAHA SMAF            @tab  X  @tab  X

@@ -415,7 +415,7 @@ OBJS-$(CONFIG_WNV1_DECODER)            += wnv1.o

 OBJS-$(CONFIG_WS_SND1_DECODER)         += ws-snd1.o

 OBJS-$(CONFIG_XAN_DPCM_DECODER)        += dpcm.o

 OBJS-$(CONFIG_XAN_WC3_DECODER)         += xan.o

-OBJS-$(CONFIG_XAN_WC4_DECODER)         += xan.o

+OBJS-$(CONFIG_XAN_WC4_DECODER)         += xxan.o

 OBJS-$(CONFIG_XL_DECODER)              += xl.o

 OBJS-$(CONFIG_XSUB_DECODER)            += xsubdec.o

 OBJS-$(CONFIG_XSUB_ENCODER)            += xsubenc.o

@@ -214,6 +214,7 @@ void avcodec_register_all(void)

     REGISTER_DECODER (WMV3_VDPAU, wmv3_vdpau);

     REGISTER_DECODER (WNV1, wnv1);

     REGISTER_DECODER (XAN_WC3, xan_wc3);

+    REGISTER_DECODER (XAN_WC4, xan_wc4);

     REGISTER_DECODER (XL, xl);

     REGISTER_DECODER (YOP, yop);

     REGISTER_ENCDEC  (ZLIB, zlib);

@@ -32,7 +32,7 @@

 #include "libavutil/cpu.h"

 #define LIBAVCODEC_VERSION_MAJOR 52

-#define LIBAVCODEC_VERSION_MINOR 109

+#define LIBAVCODEC_VERSION_MINOR 110

 #define LIBAVCODEC_VERSION_MICRO  0

 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \

new file mode 100644

@@ -0,0 +1,429 @@

+/*

+ * Wing Commander/Xan Video Decoder

+ * Copyright (C) 2011 Konstantin Shishkov

+ * based on work by Mike Melanson

+ *

+ * 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

+ */

+

+#include "avcodec.h"

+#include "libavutil/intreadwrite.h"

+#include "bytestream.h"

+#define ALT_BITSTREAM_READER_LE

+#include "get_bits.h"

+// for av_memcpy_backptr

+#include "libavutil/lzo.h"

+

+typedef struct XanContext {

+    AVCodecContext *avctx;

+    AVFrame pic;

+

+    uint8_t *y_buffer;

+    uint8_t *scratch_buffer;

+    int     buffer_size;

+} XanContext;

+

+static av_cold int xan_decode_init(AVCodecContext *avctx)

+{

+    XanContext *s = avctx->priv_data;

+

+    s->avctx = avctx;

+

+    avctx->pix_fmt = PIX_FMT_YUV420P;

+

+    s->buffer_size = avctx->width * avctx->height;

+    s->y_buffer = av_malloc(s->buffer_size);

+    if (!s->y_buffer)

+        return AVERROR(ENOMEM);

+    s->scratch_buffer = av_malloc(s->buffer_size + 130);

+    if (!s->scratch_buffer) {

+        av_freep(&s->y_buffer);

+        return AVERROR(ENOMEM);

+    }

+

+    return 0;

+}

+

+static int xan_unpack_luma(const uint8_t *src, const int src_size,

+                           uint8_t *dst, const int dst_size)

+{

+   int tree_size, eof;

+   const uint8_t *tree;

+   int bits, mask;

+   int tree_root, node;

+   const uint8_t *dst_end = dst + dst_size;

+   const uint8_t *src_end = src + src_size;

+

+   tree_size = *src++;

+   eof       = *src++;

+   tree      = src - eof * 2 - 2;

+   tree_root = eof + tree_size;

+   src += tree_size * 2;

+

+   node = tree_root;

+   bits = *src++;

+   mask = 0x80;

+   for (;;) {

+       int bit = !!(bits & mask);

+       mask >>= 1;

+       node = tree[node*2 + bit];

+       if (node == eof)

+           break;

+       if (node < eof) {

+           *dst++ = node;

+           if (dst > dst_end)

+               break;

+           node = tree_root;

+       }

+       if (!mask) {

+           bits = *src++;

+           if (src > src_end)

+               break;

+           mask = 0x80;

+       }

+   }

+   return dst != dst_end;

+}

+

+/* almost the same as in xan_wc3 decoder */

+static int xan_unpack(uint8_t *dest, const int dest_len,

+                      const uint8_t *src, const int src_len)

+{

+    uint8_t opcode;

+    int size;

+    uint8_t *orig_dest = dest;

+    const uint8_t *src_end = src + src_len;

+    const uint8_t *dest_end = dest + dest_len;

+

+    while (dest < dest_end) {

+        opcode = *src++;

+

+        if (opcode < 0xe0) {

+            int size2, back;

+            if ((opcode & 0x80) == 0) {

+                size  = opcode & 3;

+                back  = ((opcode & 0x60) << 3) + *src++ + 1;

+                size2 = ((opcode & 0x1c) >> 2) + 3;

+            } else if ((opcode & 0x40) == 0) {

+                size  = *src >> 6;

+                back  = (bytestream_get_be16(&src) & 0x3fff) + 1;

+                size2 = (opcode & 0x3f) + 4;

+            } else {

+                size  = opcode & 3;

+                back  = ((opcode & 0x10) << 12) + bytestream_get_be16(&src) + 1;

+                size2 = ((opcode & 0x0c) <<  6) + *src++ + 5;

+                if (size + size2 > dest_end - dest)

+                    break;

+            }

+            if (src + size > src_end || dest + size + size2 > dest_end)

+                return -1;

+            bytestream_get_buffer(&src, dest, size);

+            dest += size;

+            av_memcpy_backptr(dest, back, size2);

+            dest += size2;

+        } else {

+            int finish = opcode >= 0xfc;

+

+            size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;

+            if (src + size > src_end || dest + size > dest_end)

+                return -1;

+            bytestream_get_buffer(&src, dest, size);

+            dest += size;

+            if (finish)

+                break;

+        }

+    }

+    return dest - orig_dest;

+}

+

+static int xan_decode_chroma(AVCodecContext *avctx, AVPacket *avpkt)

+{

+    const uint8_t *buf = avpkt->data;

+    XanContext *s = avctx->priv_data;

+    uint8_t *U, *V;

+    unsigned chroma_off;

+    int val, uval, vval;

+    int i, j;

+    const uint8_t *src, *src_end;

+    const uint8_t *table;

+    int mode, offset, dec_size;

+

+    chroma_off = AV_RL32(buf + 4);

+    if (!chroma_off)

+        return 0;

+    if (chroma_off + 10 >= avpkt->size) {

+        av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");

+        return -1;

+    }

+    src    = avpkt->data + 4 + chroma_off;

+    table  = src + 2;

+    mode   = bytestream_get_le16(&src);

+    offset = bytestream_get_le16(&src) * 2;

+

+    if (src - avpkt->data >= avpkt->size - offset) {

+        av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");

+        return -1;

+    }

+

+    memset(s->scratch_buffer, 0, s->buffer_size);

+    dec_size = xan_unpack(s->scratch_buffer, s->buffer_size, src + offset,

+                          avpkt->size - offset - (src - avpkt->data));

+    if (dec_size < 0) {

+        av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");

+        return -1;

+    }

+

+    U = s->pic.data[1];

+    V = s->pic.data[2];

+    src     = s->scratch_buffer;

+    src_end = src + dec_size;

+    if (mode) {

+        for (j = 0; j < avctx->height >> 1; j++) {

+            for (i = 0; i < avctx->width >> 1; i++) {

+                val = *src++;

+                if (val) {

+                    val  = AV_RL16(table + (val << 1));

+                    uval = (val >> 3) & 0xF8;

+                    vval = (val >> 8) & 0xF8;

+                    U[i] = uval | (uval >> 5);

+                    V[i] = vval | (vval >> 5);

+                }

+                if (src == src_end)

+                    return 0;

+            }

+            U += s->pic.linesize[1];

+            V += s->pic.linesize[2];

+        }

+    } else {

+        uint8_t *U2 = U + s->pic.linesize[1];

+        uint8_t *V2 = V + s->pic.linesize[2];

+

+        for (j = 0; j < avctx->height >> 2; j++) {

+            for (i = 0; i < avctx->width >> 1; i += 2) {

+                val = *src++;

+                if (val) {

+                    val  = AV_RL16(table + (val << 1));

+                    uval = (val >> 3) & 0xF8;

+                    vval = (val >> 8) & 0xF8;

+                    U[i] = U[i+1] = U2[i] = U2[i+1] = uval | (uval >> 5);

+                    V[i] = V[i+1] = V2[i] = V2[i+1] = vval | (vval >> 5);

+                }

+            }

+            U  += s->pic.linesize[1] * 2;

+            V  += s->pic.linesize[2] * 2;

+            U2 += s->pic.linesize[1] * 2;

+            V2 += s->pic.linesize[2] * 2;

+        }

+    }

+

+    return 0;

+}

+

+static int xan_decode_frame_type0(AVCodecContext *avctx, AVPacket *avpkt)

+{

+    const uint8_t *buf = avpkt->data;

+    XanContext *s = avctx->priv_data;

+    uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;

+    unsigned  chroma_off, corr_off;

+    int cur, last, size;

+    int i, j;

+    int ret;

+

+    corr_off   = AV_RL32(buf + 8);

+    chroma_off = AV_RL32(buf + 4);

+

+    if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)

+        return ret;

+

+    size = avpkt->size - 4;

+    if (corr_off >= avpkt->size) {

+        av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");

+        corr_off = 0;

+    }

+    if (corr_off)

+        size = corr_off;

+    if (chroma_off)

+        size = FFMIN(size, chroma_off);

+    ret = xan_unpack_luma(buf + 12, size, src, s->buffer_size >> 1);

+    if (ret) {

+        av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");

+        return ret;

+    }

+

+    ybuf = s->y_buffer;

+    last = *src++;

+    ybuf[0] = last << 1;

+    for (j = 1; j < avctx->width - 1; j += 2) {

+        cur = (last + *src++) & 0x1F;

+        ybuf[j]   = last + cur;

+        ybuf[j+1] = cur << 1;

+        last = cur;

+    }

+    ybuf[j]  = last << 1;

+    prev_buf = ybuf;

+    ybuf += avctx->width;

+

+    for (i = 1; i < avctx->height; i++) {

+        last = ((prev_buf[0] >> 1) + *src++) & 0x1F;

+        ybuf[0] = last << 1;

+        for (j = 1; j < avctx->width - 1; j += 2) {

+            cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;

+            ybuf[j]   = last + cur;

+            ybuf[j+1] = cur << 1;

+            last = cur;

+        }

+        ybuf[j] = last << 1;

+        prev_buf = ybuf;

+        ybuf += avctx->width;

+    }

+

+    if (corr_off) {

+        int corr_end, dec_size;

+

+        corr_end = avpkt->size;

+        if (chroma_off > corr_off)

+            corr_end = chroma_off;

+        dec_size = xan_unpack(s->scratch_buffer, s->buffer_size,

+                              avpkt->data + 8 + corr_off,

+                              corr_end - corr_off);

+        if (dec_size < 0)

+            dec_size = 0;

+        for (i = 0; i < dec_size; i++)

+            s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;

+    }

+

+    src  = s->y_buffer;

+    ybuf = s->pic.data[0];

+    for (j = 0; j < avctx->height; j++) {

+        for (i = 0; i < avctx->width; i++)

+            ybuf[i] = (src[i] << 2) | (src[i] >> 3);

+        src  += avctx->width;

+        ybuf += s->pic.linesize[0];

+    }

+

+    return 0;

+}

+

+static int xan_decode_frame_type1(AVCodecContext *avctx, AVPacket *avpkt)

+{

+    const uint8_t *buf = avpkt->data;

+    XanContext *s = avctx->priv_data;

+    uint8_t *ybuf, *src = s->scratch_buffer;

+    int cur, last;

+    int i, j;

+    int ret;

+

+    if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)

+        return ret;

+

+    ret = xan_unpack_luma(buf + 16, avpkt->size - 16, src,

+                          s->buffer_size >> 1);

+    if (ret) {

+        av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");

+        return ret;

+    }

+

+    ybuf = s->y_buffer;

+    for (i = 0; i < avctx->height; i++) {

+        last = (ybuf[0] + (*src++ << 1)) & 0x3F;

+        ybuf[0] = last;

+        for (j = 1; j < avctx->width - 1; j += 2) {

+            cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;

+            ybuf[j]   = (last + cur) >> 1;

+            ybuf[j+1] = cur;

+            last = cur;

+        }

+        ybuf[j] = last;

+        ybuf += avctx->width;

+    }

+

+    src = s->y_buffer;

+    ybuf = s->pic.data[0];

+    for (j = 0; j < avctx->height; j++) {

+        for (i = 0; i < avctx->width; i++)

+            ybuf[i] = (src[i] << 2) | (src[i] >> 3);

+        src  += avctx->width;

+        ybuf += s->pic.linesize[0];

+    }

+

+    return 0;

+}

+

+static int xan_decode_frame(AVCodecContext *avctx,

+                            void *data, int *data_size,

+                            AVPacket *avpkt)

+{

+    XanContext *s = avctx->priv_data;

+    int ftype;

+    int ret;

+

+    s->pic.reference = 1;

+    s->pic.buffer_hints = FF_BUFFER_HINTS_VALID |

+                          FF_BUFFER_HINTS_PRESERVE |

+                          FF_BUFFER_HINTS_REUSABLE;

+    if ((ret = avctx->reget_buffer(avctx, &s->pic))) {

+        av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");

+        return ret;

+    }

+

+    ftype = AV_RL32(avpkt->data);

+    switch (ftype) {

+    case 0:

+        ret = xan_decode_frame_type0(avctx, avpkt);

+        break;

+    case 1:

+        ret = xan_decode_frame_type1(avctx, avpkt);

+        break;

+    default:

+        av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);

+        return -1;

+    }

+    if (ret)

+        return ret;

+

+    *data_size = sizeof(AVFrame);

+    *(AVFrame*)data = s->pic;

+

+    return avpkt->size;

+}

+

+static av_cold int xan_decode_end(AVCodecContext *avctx)

+{

+    XanContext *s = avctx->priv_data;

+

+    if (s->pic.data[0])

+        avctx->release_buffer(avctx, &s->pic);

+

+    av_freep(&s->y_buffer);

+    av_freep(&s->scratch_buffer);

+

+    return 0;

+}

+

+AVCodec ff_xan_wc4_decoder = {

+    "xan_wc4",

+    AVMEDIA_TYPE_VIDEO,

+    CODEC_ID_XAN_WC4,

+    sizeof(XanContext),

+    xan_decode_init,

+    NULL,

+    xan_decode_end,

+    xan_decode_frame,

+    CODEC_CAP_DR1,

+    .long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),

+};

+