DXA demuxer and decoder

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

Changelog

@@ -73,6 +73,7 @@ version <next>
 - WMA encoder
 - GSM-MS encoder and decoder
 - DCA decoder
+- DXA demuxer and decoder
 
 version 0.4.9-pre1:
 

MAINTAINERS

@@ -114,6 +114,7 @@ Codecs:
   cook.c, cookdata.h                    Benjamin Larsson
   cscd.c                                Reimar Doeffinger
   dpcm.c                                Mike Melanson
+  dxa.c                                 Kostya Shishkov
   dv.c                                  Roman Shaposhnik
   ffv1.c                                Michael Niedermayer
   flac.c                                Alex Beregszaszi
@@ -202,6 +203,7 @@ Muxers/Demuxers:
   crc.c                                 Michael Niedermayer
   daud.c                                Reimar Doeffinger
   dc1394.c, dv.c                        Roman Shaposhnik
+  dxa.c                                 Kostya Shishkov
   flic.c                                Mike Melanson
   flvdec.c, flvenc.c                    Michael Niedermayer
   gxf.c                                 Reimar Doeffinger

configure

@@ -644,6 +644,7 @@ CMDLINE_SELECT="
     static
 "
 
+dxa_decoder_deps="zlib"
 flashsv_decoder_deps="zlib"
 flashsv_encoder_deps="zlib"
 mpeg_xvmc_decoder_deps="xvmc"

doc/ffmpeg-doc.texi

@@ -898,6 +898,9 @@ library:
 @tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
 @item SEQ @tab    @tab X
 @tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
+@item DXA @tab    @tab X
+@tab This format is used in non-Windows version of Feeble Files game and
+different game cutscenes repacked for use with ScummVM.
 @end multitable
 
 @code{X} means that encoding (resp. decoding) is supported.
@@ -1005,6 +1008,7 @@ following image formats are supported:
 @item VMware Video           @tab     @tab  X @tab Codec used in videos captured by VMware.
 @item Cin Video              @tab     @tab  X @tab Codec used in Delphine Software games.
 @item Tiertex Seq Video      @tab     @tab  X @tab Codec used in DOS CDROM FlashBack game.
+@item DXA Video              @tab     @tab  X @tab Codec originally used in Feeble Files game.
 @end multitable
 
 @code{X} means that encoding (resp. decoding) is supported.

libavcodec/Makefile

@@ -72,6 +72,7 @@ OBJS-$(CONFIG_DVDSUB_DECODER)          += dvdsubdec.o
 OBJS-$(CONFIG_DVDSUB_ENCODER)          += dvdsubenc.o
 OBJS-$(CONFIG_DVVIDEO_DECODER)         += dv.o
 OBJS-$(CONFIG_DVVIDEO_ENCODER)         += dv.o
+OBJS-$(CONFIG_DXA_DECODER)             += dxa.o
 OBJS-$(CONFIG_EIGHTBPS_DECODER)        += 8bps.o
 OBJS-$(CONFIG_FFV1_DECODER)            += ffv1.o
 OBJS-$(CONFIG_FFV1_ENCODER)            += ffv1.o

libavcodec/allcodecs.c

@@ -67,6 +67,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER(DCA, dca);
     REGISTER_DECODER(DSICINVIDEO, dsicinvideo);
     REGISTER_ENCDEC (DVVIDEO, dvvideo);
+    REGISTER_DECODER(DXA, dxa);
     REGISTER_DECODER(EIGHTBPS, eightbps);
     REGISTER_ENCDEC (FFV1, ffv1);
     REGISTER_ENCDEC (FFVHUFF, ffvhuff);

libavcodec/avcodec.h

@@ -37,8 +37,8 @@ extern "C" {
 #define AV_STRINGIFY(s)         AV_TOSTRING(s)
 #define AV_TOSTRING(s) #s
 
-#define LIBAVCODEC_VERSION_INT  ((51<<16)+(38<<8)+0)
+#define LIBAVCODEC_VERSION_INT  ((51<<16)+(39<<8)+0)
-#define LIBAVCODEC_VERSION      51.38.0
+#define LIBAVCODEC_VERSION      51.39.0
 #define LIBAVCODEC_BUILD        LIBAVCODEC_VERSION_INT
 
 #define LIBAVCODEC_IDENT        "Lavc" AV_STRINGIFY(LIBAVCODEC_VERSION)
@@ -150,6 +150,7 @@ enum CodecID {
     CODEC_ID_TIFF,
     CODEC_ID_GIF,
     CODEC_ID_FFH264,
+    CODEC_ID_DXA,
 
     /* various pcm "codecs" */
     CODEC_ID_PCM_S16LE= 0x10000,
@@ -2232,6 +2233,7 @@ extern AVCodec dca_decoder;
 extern AVCodec dsicinaudio_decoder;
 extern AVCodec dsicinvideo_decoder;
 extern AVCodec dvvideo_decoder;
+extern AVCodec dxa_decoder;
 extern AVCodec eightbps_decoder;
 extern AVCodec ffv1_decoder;
 extern AVCodec ffvhuff_decoder;

libavcodec/dxa.c

@@ -0,0 +1,333 @@
+/*
+ * 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
+};
+

libavformat/Makefile

@@ -34,6 +34,7 @@ OBJS-$(CONFIG_DSICIN_DEMUXER)            += dsicin.o
 OBJS-$(CONFIG_DV_DEMUXER)                += dv.o
 OBJS-$(CONFIG_DV_MUXER)                  += dvenc.o
 OBJS-$(CONFIG_DV1394_DEMUXER)            += dv1394.o
+OBJS-$(CONFIG_DXA_DEMUXER)               += dxa.o
 OBJS-$(CONFIG_EA_DEMUXER)                += electronicarts.o
 OBJS-$(CONFIG_FFM_DEMUXER)               += ffm.o
 OBJS-$(CONFIG_FFM_MUXER)                 += ffm.o

libavformat/allformats.c

@@ -65,6 +65,7 @@ void av_register_all(void)
     REGISTER_DEMUXER (DTS, dts);
     REGISTER_MUXDEMUX(DV, dv);
     REGISTER_DEMUXER (DV1394, dv1394);
+    REGISTER_DEMUXER (DXA, dxa);
     REGISTER_DEMUXER (EA, ea);
     REGISTER_MUXDEMUX(FFM, ffm);
     REGISTER_MUXDEMUX(FLAC, flac);

libavformat/allformats.h

@@ -47,6 +47,7 @@ extern AVInputFormat dsicin_demuxer;
 extern AVInputFormat dv1394_demuxer;
 extern AVInputFormat dv_demuxer;
 extern AVOutputFormat dv_muxer;
+extern AVInputFormat dxa_demuxer;
 extern AVInputFormat ea_demuxer;
 extern AVInputFormat ffm_demuxer;
 extern AVOutputFormat ffm_muxer;

libavformat/avformat.h

@@ -25,8 +25,8 @@
 extern "C" {
 #endif
 
-#define LIBAVFORMAT_VERSION_INT ((51<<16)+(10<<8)+0)
+#define LIBAVFORMAT_VERSION_INT ((51<<16)+(11<<8)+0)
-#define LIBAVFORMAT_VERSION     51.10.0
+#define LIBAVFORMAT_VERSION     51.11.0
 #define LIBAVFORMAT_BUILD       LIBAVFORMAT_VERSION_INT
 
 #define LIBAVFORMAT_IDENT       "Lavf" AV_STRINGIFY(LIBAVFORMAT_VERSION)

libavformat/dxa.c

@@ -0,0 +1,214 @@
+/*
+ * DXA demuxer
+ * 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
+ */
+
+#include "avformat.h"
+#include "riff.h"
+
+#define DXA_EXTRA_SIZE  9
+
+typedef struct{
+    int frames;
+    int has_sound;
+    int bpc;
+    uint32_t bytes_left;
+    int64_t wavpos, vidpos;
+    int readvid;
+}DXAContext;
+
+static int dxa_probe(AVProbeData *p)
+{
+    /* check file header */
+    if (p->buf_size <= 4)
+        return 0;
+    if (p->buf[0] == 'D' && p->buf[1] == 'E' &&
+        p->buf[2] == 'X' && p->buf[3] == 'A')
+        return AVPROBE_SCORE_MAX;
+    else
+        return 0;
+}
+
+static int dxa_read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+    ByteIOContext *pb = &s->pb;
+    DXAContext *c = s->priv_data;
+    AVStream *st, *ast;
+    uint32_t tag;
+    int32_t fps;
+    int w, h;
+    int num, den;
+    int flags;
+
+    tag = get_le32(pb);
+    if (tag != MKTAG('D', 'E', 'X', 'A'))
+        return -1;
+    flags = get_byte(pb);
+    c->frames = get_be16(pb);
+    if(!c->frames){
+        av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
+        return -1;
+    }
+
+    fps = get_be32(pb);
+    if(fps > 0){
+        den = 1000;
+        num = fps;
+    }else if (fps < 0){
+        den = 100000;
+        num = -fps;
+    }else{
+        den = 10;
+        num = 1;
+    }
+    w = get_be16(pb);
+    h = get_be16(pb);
+    c->has_sound = 0;
+
+    st = av_new_stream(s, 0);
+    if (!st)
+        return -1;
+
+    // Parse WAV data header
+    if(get_le32(pb) == MKTAG('W', 'A', 'V', 'E')){
+        uint32_t size, fsize;
+        c->has_sound = 1;
+        size = get_be32(pb);
+        c->vidpos = url_ftell(pb) + size;
+        url_fskip(pb, 16);
+        fsize = get_le32(pb);
+
+        ast = av_new_stream(s, 0);
+        if (!ast)
+            return -1;
+        get_wav_header(pb, ast->codec, fsize);
+        // find 'data' chunk
+        while(url_ftell(pb) < c->vidpos && !url_feof(pb)){
+            tag = get_le32(pb);
+            fsize = get_le32(pb);
+            if(tag == MKTAG('d', 'a', 't', 'a')) break;
+            url_fskip(pb, fsize);
+        }
+        c->bpc = (fsize + c->frames - 1) / c->frames;
+        if(ast->codec->block_align)
+            c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align;
+        c->bytes_left = fsize;
+        c->wavpos = url_ftell(pb);
+        url_fseek(pb, c->vidpos, SEEK_SET);
+    }
+
+    /* now we are ready: build format streams */
+    st->codec->codec_type = CODEC_TYPE_VIDEO;
+    st->codec->codec_id   = CODEC_ID_DXA;
+    st->codec->width      = w;
+    st->codec->height     = h;
+    av_reduce(&den, &num, den, num, (1UL<<31)-1);
+    av_set_pts_info(st, 33, num, den);
+    /* flags & 0x80 means that image is interlaced,
+     * flags & 0x40 means that image has double height
+     * either way set true height
+     */
+    if(flags & 0xC0){
+        st->codec->height >>= 1;
+    }
+    c->readvid = !c->has_sound;
+    c->vidpos  = url_ftell(pb);
+    s->start_time = 0;
+    s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
+    av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
+
+    return 0;
+}
+
+static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    DXAContext *c = s->priv_data;
+    int ret;
+    uint32_t size;
+    uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
+    int pal_size = 0;
+
+    if(!c->readvid && c->has_sound && c->bytes_left){
+        c->readvid = 1;
+        url_fseek(&s->pb, c->wavpos, SEEK_SET);
+        size = FFMIN(c->bytes_left, c->bpc);
+        ret = av_get_packet(&s->pb, pkt, size);
+        pkt->stream_index = 1;
+        if(ret != size)
+            return AVERROR_IO;
+        c->bytes_left -= size;
+        c->wavpos = url_ftell(&s->pb);
+        return 0;
+    }
+    url_fseek(&s->pb, c->vidpos, SEEK_SET);
+    while(!url_feof(&s->pb) && c->frames){
+        get_buffer(&s->pb, buf, 4);
+        switch(AV_RL32(buf)){
+        case MKTAG('N', 'U', 'L', 'L'):
+            if(av_new_packet(pkt, 4 + pal_size) < 0)
+                return AVERROR_NOMEM;
+            pkt->stream_index = 0;
+            if(pal_size) memcpy(pkt->data, pal, pal_size);
+            memcpy(pkt->data + pal_size, buf, 4);
+            c->frames--;
+            c->vidpos = url_ftell(&s->pb);
+            c->readvid = 0;
+            return 0;
+        case MKTAG('C', 'M', 'A', 'P'):
+            pal_size = 768+4;
+            memcpy(pal, buf, 4);
+            get_buffer(&s->pb, pal + 4, 768);
+            break;
+        case MKTAG('F', 'R', 'A', 'M'):
+            get_buffer(&s->pb, buf + 4, DXA_EXTRA_SIZE - 4);
+            size = AV_RB32(buf + 5);
+            if(size > 0xFFFFFF){
+                av_log(s, AV_LOG_ERROR, "Frame size is too big: %d\n", size);
+                return -1;
+            }
+            if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)
+                return AVERROR_NOMEM;
+            memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
+            ret = get_buffer(&s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
+            if(ret != size){
+                av_free_packet(pkt);
+                return AVERROR_IO;
+            }
+            if(pal_size) memcpy(pkt->data, pal, pal_size);
+            pkt->stream_index = 0;
+            c->frames--;
+            c->vidpos = url_ftell(&s->pb);
+            c->readvid = 0;
+            return 0;
+        default:
+            av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]);
+            return -1;
+        }
+    }
+    return AVERROR(EIO);
+}
+
+AVInputFormat dxa_demuxer = {
+    "dxa",
+    "dxa",
+    sizeof(DXAContext),
+    dxa_probe,
+    dxa_read_header,
+    dxa_read_packet,
+};