first pass at an experimental 4xm demuxer

Originally committed as revision 1903 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/4xm.c

+/*
+ * 4X Technologies .4xm File Demuxer (no muxer)
+ * Copyright (c) 2003  The ffmpeg Project
+ *
+ * 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 4xm.c
+ * 4X Technologies file demuxer
+ * by Mike Melanson (melanson@pcisys.net)
+ * for more information on the .4xm file format, visit:
+ *   http://www.pcisys.net/~melanson/codecs/
+ */
+
+#include "avformat.h"
+
+#define LE_16(x)  ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0])
+#define LE_32(x)  ((((uint8_t*)(x))[3] << 24) | \
+                   (((uint8_t*)(x))[2] << 16) | \
+                   (((uint8_t*)(x))[1] << 8) | \
+                    ((uint8_t*)(x))[0])
+#define BE_16(x)  ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
+#define BE_32(x)  ((((uint8_t*)(x))[0] << 24) | \
+                   (((uint8_t*)(x))[1] << 16) | \
+                   (((uint8_t*)(x))[2] << 8) | \
+                    ((uint8_t*)(x))[3])
+
+#define FOURCC_TAG( ch0, ch1, ch2, ch3 ) \
+        ( (long)(unsigned char)(ch3) | \
+        ( (long)(unsigned char)(ch2) << 8 ) | \
+        ( (long)(unsigned char)(ch1) << 16 ) | \
+        ( (long)(unsigned char)(ch0) << 24 ) )
+
+#define  RIFF_TAG FOURCC_TAG('R', 'I', 'F', 'F')
+#define _4XMV_TAG FOURCC_TAG('4', 'X', 'M', 'V')
+#define  LIST_TAG FOURCC_TAG('L', 'I', 'S', 'T')
+#define  HEAD_TAG FOURCC_TAG('H', 'E', 'A', 'D')
+#define  TRK__TAG FOURCC_TAG('T', 'R', 'K', '_')
+#define  MOVI_TAG FOURCC_TAG('M', 'O', 'V', 'I')
+#define  VTRK_TAG FOURCC_TAG('V', 'T', 'R', 'K')
+#define  STRK_TAG FOURCC_TAG('S', 'T', 'R', 'K')
+#define  name_TAG FOURCC_TAG('n', 'a', 'm', 'e')
+#define  vtrk_TAG FOURCC_TAG('v', 't', 'r', 'k')
+#define  strk_TAG FOURCC_TAG('s', 't', 'r', 'k')
+#define  ifrm_TAG FOURCC_TAG('i', 'f', 'r', 'm')
+#define  pfrm_TAG FOURCC_TAG('p', 'f', 'r', 'm')
+#define  cfrm_TAG FOURCC_TAG('c', 'f', 'r', 'm')
+#define  snd__TAG FOURCC_TAG('s', 'n', 'd', '_')
+#define  _TAG FOURCC_TAG('', '', '', '')
+
+#define vtrk_SIZE 0x44
+#define strk_SIZE 0x28
+
+#define GET_LIST_HEADER() \
+    fourcc_tag = get_be32(pb); \
+    size = get_le32(pb); \
+    if (fourcc_tag != LIST_TAG) \
+        return AVERROR_INVALIDDATA; \
+    fourcc_tag = get_be32(pb);
+
+typedef struct AudioTrack {
+    int sample_rate;
+    int bits;
+    int channels;
+} AudioTrack;
+
+typedef struct FourxmDemuxContext {
+    int width;
+    int height;
+    int track_count;
+    AudioTrack *tracks;
+    int selected_track;
+} FourxmDemuxContext;
+
+static int fourxm_probe(AVProbeData *p)
+{
+    if ((BE_32(&p->buf[0]) != RIFF_TAG) ||
+        (BE_32(&p->buf[8]) != _4XMV_TAG))
+        return 0;
+
+printf ("  detected .4xm file\n");
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int fourxm_read_header(AVFormatContext *s,
+                             AVFormatParameters *ap)
+{
+    ByteIOContext *pb = &s->pb;
+    unsigned int fourcc_tag;
+    unsigned int size;
+    int header_size;
+    FourxmDemuxContext *fourxm = (FourxmDemuxContext *)s->priv_data;
+    unsigned char *header;
+    int i;
+    int current_track = -1;
+    AVStream *st;
+
+    fourxm->track_count = 0;
+    fourxm->tracks = NULL;
+    fourxm->selected_track = 0;
+
+    /* skip the first 3 32-bit numbers */
+    url_fseek(pb, 12, SEEK_CUR);
+
+    /* check for LIST-HEAD */
+    GET_LIST_HEADER();
+    header_size = size - 4;
+    if (fourcc_tag != HEAD_TAG)
+        return AVERROR_INVALIDDATA;
+
+    /* allocate space for the header and load the whole thing */
+    header = av_malloc(header_size);
+    if (!header)
+        return AVERROR_NOMEM;
+    if (get_buffer(pb, header, header_size) != header_size)
+        return AVERROR_IO;
+
+    /* take the lazy approach and search for any and all vtrk and strk chunks */
+    for (i = 0; i < header_size - 8; i++) {
+        fourcc_tag = BE_32(&header[i]);
+        size = LE_32(&header[i + 4]);
+
+        if (fourcc_tag == vtrk_TAG) {
+            /* check that there is enough data */
+            if (size != vtrk_SIZE) {
+                av_free(header);
+                return AVERROR_INVALIDDATA;
+            }
+            fourxm->width = LE_32(&header[i + 36]);
+            fourxm->height = LE_32(&header[i + 40]);
+            i += 8 + size;
+        } else if (fourcc_tag == strk_TAG) {
+            /* check that there is enough data */
+            if (size != strk_SIZE) {
+                av_free(header);
+                return AVERROR_INVALIDDATA;
+            }
+            current_track = LE_32(&header[i + 8]);
+            if (current_track + 1 > fourxm->track_count) {
+                fourxm->track_count++;
+                fourxm->tracks = av_realloc(fourxm->tracks, fourxm->track_count);
+                if (!fourxm->tracks) {
+                    av_free(header);
+                    return AVERROR_NOMEM;
+                }
+            }
+            fourxm->tracks[current_track].channels = LE_32(&header[i + 36]);
+            fourxm->tracks[current_track].sample_rate = LE_32(&header[i + 40]);
+            fourxm->tracks[current_track].bits = LE_32(&header[i + 44]);
+            i += 8 + size;
+        }
+    }
+
+    av_free(header);
+
+    /* skip over the LIST-MOVI chunk (which is where the stream should be */
+    GET_LIST_HEADER();
+    if (fourcc_tag != MOVI_TAG)
+        return AVERROR_INVALIDDATA;
+
+    if (current_track > -1) {
+        st = av_new_stream(s, 0);
+        if (!st)
+            return AVERROR_NOMEM;
+
+        st->codec.codec_type = CODEC_TYPE_AUDIO;
+        st->codec.codec_tag = 1;
+        st->codec.channels = fourxm->tracks[current_track].channels;
+        st->codec.sample_rate = fourxm->tracks[current_track].sample_rate;
+        st->codec.bits_per_sample = fourxm->tracks[current_track].bits;
+        st->codec.bit_rate = st->codec.channels * st->codec.sample_rate *
+            st->codec.bits_per_sample;
+        st->codec.block_align = st->codec.channels * st->codec.bits_per_sample;
+        if (st->codec.bits_per_sample == 8)
+            st->codec.codec_id = CODEC_ID_PCM_U8;
+        else
+            st->codec.codec_id = CODEC_ID_PCM_S16LE;
+    }
+
+    return 0;
+}
+
+static int fourxm_read_packet(AVFormatContext *s,
+                             AVPacket *pkt)
+{
+    FourxmDemuxContext *fourxm = s->priv_data;
+    ByteIOContext *pb = &s->pb;
+    unsigned int fourcc_tag;
+    unsigned int size;
+    int ret = 0;
+    int track_number;
+    int packet_read = 0;
+
+    while (!packet_read) {
+
+        fourcc_tag = get_be32(pb);
+        size = get_le32(pb);
+        if (fourcc_tag == LIST_TAG) {
+            /* skip the LIST-FRAM tag and get the next fourcc */
+            get_be32(pb);
+            fourcc_tag = get_be32(pb);
+            size = get_le32(pb);
+        }
+
+        if (url_feof(pb))
+            return -EIO;
+
+        switch (fourcc_tag) {
+
+        case ifrm_TAG:
+        case pfrm_TAG:
+        case cfrm_TAG:
+printf (" %cfrm chunk\n", (char)(fourcc_tag >> 24) & 0xFF);
+url_fseek(pb, size, SEEK_CUR);
+            break;
+
+        case snd__TAG:
+printf (" snd_ chunk, ");
+            track_number = get_le32(pb);
+            size = get_le32(pb);
+            if (track_number == fourxm->selected_track) {
+printf ("correct track, dispatching...\n");
+                if (av_new_packet(pkt, size))
+                    return -EIO;
+                ret = get_buffer(&s->pb, pkt->data, size);
+                if (ret < 0)
+                    av_free_packet(pkt);
+                packet_read = 1;
+            } else {
+printf ("wrong track, skipping...\n");
+                url_fseek(pb, size, SEEK_CUR);
+            }
+            break;
+
+        default:
+            url_fseek(pb, size, SEEK_CUR);
+            break;
+        }
+    }
+
+    return ret;
+}
+
+static int fourxm_read_close(AVFormatContext *s)
+{
+    FourxmDemuxContext *fourxm = (FourxmDemuxContext *)s->priv_data;
+
+    av_free(fourxm->tracks);
+
+    return 0;
+}
+
+static AVInputFormat fourxm_iformat = {
+    "4xm",
+    "4X Technologies format",
+    sizeof(FourxmDemuxContext),
+    fourxm_probe,
+    fourxm_read_header,
+    fourxm_read_packet,
+    fourxm_read_close,
+};
+
+int fourxm_init(void)
+{
+    av_register_input_format(&fourxm_iformat);
+    return 0;
+}

libavformat/Makefile

@@ -14,7 +14,7 @@ PPOBJS=
 # mux and demuxes
 OBJS+=mpeg.o mpegts.o ffm.o crc.o img.o raw.o rm.o \
       avienc.o avidec.o wav.o swf.o au.o gif.o mov.o mpjpeg.o dv.o \
-      yuv4mpeg.o
+      yuv4mpeg.o 4xm.o
 
 ifeq ($(CONFIG_RISKY),yes)
 OBJS+= asf.o