DXA demuxer and decoder

Originally committed as revision 8405 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 333 insertions, 0 deletions

diff --git a/libavcodec/dxa.c b/libavcodec/dxa.c
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+++ b/libavcodec/dxa.c
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+/*
+ * Feeble Files/ScummVM DXA decoder
+ * Copyright (c) 2007 Konstantin Shishkov
+ *
+ * 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 dxa.c
+ * DXA Video decoder
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "common.h"
+#include "avcodec.h"
+
+#include <zlib.h>
+
+/*
+ * Decoder context
+ */
+typedef struct DxaDecContext {
+    AVCodecContext *avctx;
+    AVFrame pic, prev;
+
+    int dsize;
+    uint8_t *decomp_buf;
+    uint32_t pal[256];
+} DxaDecContext;
+
+static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
+static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
+
+static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, uint8_t *src, uint8_t *ref)
+{
+    uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
+    int i, j, k;
+    int type, x, y, d, d2;
+    int stride = c->pic.linesize[0];
+    uint32_t mask;
+
+    code = src  + 12;
+    data = code + ((avctx->width * avctx->height) >> 4);
+    mv   = data + AV_RB32(src + 0);
+    msk  = mv   + AV_RB32(src + 4);
+
+    for(j = 0; j < avctx->height; j += 4){
+        for(i = 0; i < avctx->width; i += 4){
+            tmp  = dst + i;
+            tmp2 = ref + i;
+            type = *code++;
+            switch(type){
+            case 4: // motion compensation
+                x = (*mv) >> 4;    if(x & 8) x = 8 - x;
+                y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
+                tmp2 += x + y*stride;
+            case 0: // skip
+            case 5: // skip in method 12
+                for(y = 0; y < 4; y++){
+                    memcpy(tmp, tmp2, 4);
+                    tmp  += stride;
+                    tmp2 += stride;
+                }
+                break;
+            case 1:  // masked change
+            case 10: // masked change with only half of pixels changed
+            case 11: // cases 10-15 are for method 12 only
+            case 12:
+            case 13:
+            case 14:
+            case 15:
+                if(type == 1){
+                    mask = AV_RB16(msk);
+                    msk += 2;
+                }else{
+                    type -= 10;
+                    mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
+                    msk++;
+                }
+                for(y = 0; y < 4; y++){
+                    for(x = 0; x < 4; x++){
+                        tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
+                        mask <<= 1;
+                    }
+                    tmp  += stride;
+                    tmp2 += stride;
+                }
+                break;
+            case 2: // fill block
+                for(y = 0; y < 4; y++){
+                    memset(tmp, data[0], 4);
+                    tmp += stride;
+                }
+                data++;
+                break;
+            case 3: // raw block
+                for(y = 0; y < 4; y++){
+                    memcpy(tmp, data, 4);
+                    data += 4;
+                    tmp  += stride;
+                }
+                break;
+            case 8: // subblocks - method 13 only
+                mask = *msk++;
+                for(k = 0; k < 4; k++){
+                    d  = ((k & 1) << 1) + ((k & 2) * stride);
+                    d2 = ((k & 1) << 1) + ((k & 2) * stride);
+                    tmp2 = ref + i + d2;
+                    switch(mask & 0xC0){
+                    case 0x80: // motion compensation
+                        x = (*mv) >> 4;    if(x & 8) x = 8 - x;
+                        y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
+                        tmp2 += x + y*stride;
+                    case 0x00: // skip
+                        tmp[d + 0         ] = tmp2[0];
+                        tmp[d + 1         ] = tmp2[1];
+                        tmp[d + 0 + stride] = tmp2[0 + stride];
+                        tmp[d + 1 + stride] = tmp2[1 + stride];
+                        break;
+                    case 0x40: // fill
+                        tmp[d + 0         ] = data[0];
+                        tmp[d + 1         ] = data[0];
+                        tmp[d + 0 + stride] = data[0];
+                        tmp[d + 1 + stride] = data[0];
+                        data++;
+                        break;
+                    case 0xC0: // raw
+                        tmp[d + 0         ] = *data++;
+                        tmp[d + 1         ] = *data++;
+                        tmp[d + 0 + stride] = *data++;
+                        tmp[d + 1 + stride] = *data++;
+                        break;
+                    }
+                    mask <<= 2;
+                }
+                break;
+            case 32: // vector quantization - 2 colors
+                mask = AV_RB16(msk);
+                msk += 2;
+                for(y = 0; y < 4; y++){
+                    for(x = 0; x < 4; x++){
+                        tmp[x] = data[mask & 1];
+                        mask >>= 1;
+                    }
+                    tmp  += stride;
+                    tmp2 += stride;
+                }
+                data += 2;
+                break;
+            case 33: // vector quantization - 3 or 4 colors
+            case 34:
+                mask = AV_RB32(msk);
+                msk += 4;
+                for(y = 0; y < 4; y++){
+                    for(x = 0; x < 4; x++){
+                        tmp[x] = data[mask & 3];
+                        mask >>= 2;
+                    }
+                    tmp  += stride;
+                    tmp2 += stride;
+                }
+                data += type - 30;
+                break;
+            default:
+                av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
+                return -1;
+            }
+        }
+        dst += stride * 4;
+        ref += stride * 4;
+    }
+    return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
+{
+    DxaDecContext * const c = (DxaDecContext *)avctx->priv_data;
+    uint8_t *outptr, *srcptr, *tmpptr;
+    unsigned long dsize;
+    int i, j, compr;
+    int stride;
+    int orig_buf_size = buf_size;
+    int pc = 0;
+
+    /* make the palette available on the way out */
+    if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
+        int r, g, b;
+
+        buf += 4;
+        for(i = 0; i < 256; i++){
+            r = *buf++;
+            g = *buf++;
+            b = *buf++;
+            c->pal[i] = (r << 16) | (g << 8) | b;
+        }
+        pc = 1;
+        buf_size -= 768+4;
+    }
+
+    if(avctx->get_buffer(avctx, &c->pic) < 0){
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return -1;
+    }
+    memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
+    c->pic.palette_has_changed = pc;
+
+    outptr = c->pic.data[0];
+    srcptr = c->decomp_buf;
+    tmpptr = c->prev.data[0];
+    stride = c->pic.linesize[0];
+
+    if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
+        compr = -1;
+    else
+        compr = buf[4];
+
+    dsize = c->dsize;
+    if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
+        av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
+        return -1;
+    }
+    switch(compr){
+    case -1:
+        c->pic.key_frame = 0;
+        c->pic.pict_type = FF_P_TYPE;
+        if(c->prev.data[0])
+            memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
+        else{ // Should happen only when first frame is 'NULL'
+            memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
+            c->pic.key_frame = 1;
+            c->pic.pict_type = FF_I_TYPE;
+        }
+        break;
+    case 2:
+    case 3:
+    case 4:
+    case 5:
+        c->pic.key_frame = !(compr & 1);
+        c->pic.pict_type = (compr & 1) ? FF_P_TYPE : FF_I_TYPE;
+        for(j = 0; j < avctx->height; j++){
+            if(compr & 1){
+                for(i = 0; i < avctx->width; i++)
+                    outptr[i] = srcptr[i] ^ tmpptr[i];
+                tmpptr += stride;
+            }else
+                memcpy(outptr, srcptr, avctx->width);
+            outptr += stride;
+            srcptr += avctx->width;
+        }
+        break;
+    case 12: // ScummVM coding
+    case 13:
+        c->pic.key_frame = 0;
+        c->pic.pict_type = FF_P_TYPE;
+        decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
+        break;
+    default:
+        av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
+        return -1;
+    }
+
+    FFSWAP(AVFrame, c->pic, c->prev);
+    if(c->pic.data[0])
+        avctx->release_buffer(avctx, &c->pic);
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = c->prev;
+
+    /* always report that the buffer was completely consumed */
+    return orig_buf_size;
+}
+
+static int decode_init(AVCodecContext *avctx)
+{
+    DxaDecContext * const c = (DxaDecContext *)avctx->priv_data;
+
+    c->avctx = avctx;
+    avctx->pix_fmt = PIX_FMT_PAL8;
+
+    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
+        return -1;
+    }
+
+    c->dsize = avctx->width * avctx->height * 2;
+    if((c->decomp_buf = av_malloc(c->dsize)) == NULL) {
+        av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int decode_end(AVCodecContext *avctx)
+{
+    DxaDecContext * const c = (DxaDecContext *)avctx->priv_data;
+
+    av_freep(&c->decomp_buf);
+    if(c->prev.data[0])
+        avctx->release_buffer(avctx, &c->prev);
+    if(c->pic.data[0])
+        avctx->release_buffer(avctx, &c->pic);
+
+    return 0;
+}
+
+AVCodec dxa_decoder = {
+    "dxa",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_DXA,
+    sizeof(DxaDecContext),
+    decode_init,
+    NULL,
+    decode_end,
+    decode_frame
+};
+