Initial revision

Originally committed as revision 2 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 347 insertions, 0 deletions

diff --git a/swfenc.c b/swfenc.c
new file mode 100644
index 0000000000..7a645e8c7a
--- /dev/null
+++ b/swfenc.c
@@ -0,0 +1,347 @@
+/*
+ * Flash Compatible Streaming Format
+ * Copyright (c) 2000 Gerard Lantau.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <netinet/in.h>
+#include <string.h>
+#include "mpegenc.h"
+
+#include <assert.h>
+
+/* should have a generic way to indicate probable size */
+#define DUMMY_FILE_SIZE   (100 * 1024 * 1024)
+#define DUMMY_DURATION    600 /* in seconds */
+
+#define TAG_END           0
+#define TAG_SHOWFRAME     1
+#define TAG_DEFINESHAPE   2
+#define TAG_FREECHARACTER 3
+#define TAG_PLACEOBJECT   4
+#define TAG_REMOVEOBJECT  5
+#define TAG_JPEG2         21
+
+#define TAG_LONG         0x100
+
+/* flags for shape definition */
+#define FLAG_MOVETO      0x01
+#define FLAG_SETFILL0    0x02
+#define FLAG_SETFILL1    0x04
+
+/* character id used */
+#define BITMAP_ID 0
+#define SHAPE_ID  1
+
+typedef struct {
+    long long duration_pos;
+    long long tag_pos;
+    int tag;
+} SWFContext;
+
+static void put_swf_tag(AVFormatContext *s, int tag)
+{
+    SWFContext *swf = s->priv_data;
+    PutByteContext *pb = &s->pb;
+
+    swf->tag_pos = put_pos(pb);
+    swf->tag = tag;
+    /* reserve some room for the tag */
+    if (tag & TAG_LONG) {
+        put_le16(pb, 0);
+        put_le32(pb, 0);
+    } else {
+        put_le16(pb, 0);
+    }
+}
+
+static void put_swf_end_tag(AVFormatContext *s)
+{
+    SWFContext *swf = s->priv_data;
+    PutByteContext *pb = &s->pb;
+    long long pos;
+    int tag_len, tag;
+
+    pos = put_pos(pb);
+    tag_len = pos - swf->tag_pos - 2;
+    tag = swf->tag;
+    put_seek(pb, swf->tag_pos, SEEK_SET);
+    if (tag & TAG_LONG) {
+        tag &= ~TAG_LONG;
+        put_le16(pb, (tag << 6) | 0x3f);
+        put_le32(pb, tag_len - 4);
+    } else {
+        assert(tag_len < 0x3f);
+        put_le16(pb, (tag << 6) | tag_len);
+    }
+    put_seek(pb, pos, SEEK_SET);
+}
+
+static inline void max_nbits(int *nbits_ptr, int val)
+{
+    int n;
+
+    if (val == 0)
+        return;
+    val = abs(val);
+    n = 1;
+    while (val != 0) {
+        n++;
+        val >>= 1;
+    }
+    if (n > *nbits_ptr)
+        *nbits_ptr = n;
+}
+
+static void put_swf_rect(PutByteContext *pb, 
+                         int xmin, int xmax, int ymin, int ymax)
+{
+    PutBitContext p;
+    UINT8 buf[256];
+    int nbits, mask;
+
+    init_put_bits(&p, buf, sizeof(buf), NULL, NULL);
+    
+    nbits = 0;
+    max_nbits(&nbits, xmin);
+    max_nbits(&nbits, xmax);
+    max_nbits(&nbits, ymin);
+    max_nbits(&nbits, ymax);
+    mask = (1 << nbits) - 1;
+
+    /* rectangle info */
+    put_bits(&p, 5, nbits);
+    put_bits(&p, nbits, xmin & mask);
+    put_bits(&p, nbits, xmax & mask);
+    put_bits(&p, nbits, ymin & mask);
+    put_bits(&p, nbits, ymax & mask);
+    
+    flush_put_bits(&p);
+    put_buffer(pb, buf, p.buf_ptr - p.buf);
+}
+
+static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
+{
+    int nbits, mask;
+
+    put_bits(pb, 1, 1); /* edge */
+    put_bits(pb, 1, 1); /* line select */
+    nbits = 2;
+    max_nbits(&nbits, dx);
+    max_nbits(&nbits, dy);
+
+    mask = (1 << nbits) - 1;
+    put_bits(pb, 4, nbits - 2); /* 16 bits precision */
+    if (dx == 0) {
+      put_bits(pb, 1, 0); 
+      put_bits(pb, 1, 1); 
+      put_bits(pb, nbits, dy & mask);
+    } else if (dy == 0) {
+      put_bits(pb, 1, 0); 
+      put_bits(pb, 1, 0); 
+      put_bits(pb, nbits, dx & mask);
+    } else {
+      put_bits(pb, 1, 1); 
+      put_bits(pb, nbits, dx & mask);
+      put_bits(pb, nbits, dy & mask);
+    }
+}
+
+#define FRAC_BITS 16
+
+/* put matrix (not size optimized */
+static void put_swf_matrix(PutByteContext *pb,
+                           int a, int b, int c, int d, int tx, int ty)
+{
+    PutBitContext p;
+    UINT8 buf[256];
+
+    init_put_bits(&p, buf, sizeof(buf), NULL, NULL);
+    
+    put_bits(&p, 1, 1); /* a, d present */
+    put_bits(&p, 5, 20); /* nb bits */
+    put_bits(&p, 20, a);
+    put_bits(&p, 20, d);
+    
+    put_bits(&p, 1, 1); /* b, c present */
+    put_bits(&p, 5, 20); /* nb bits */
+    put_bits(&p, 20, c);
+    put_bits(&p, 20, b);
+
+    put_bits(&p, 5, 20); /* nb bits */
+    put_bits(&p, 20, tx);
+    put_bits(&p, 20, ty);
+
+    flush_put_bits(&p);
+    put_buffer(pb, buf, p.buf_ptr - p.buf);
+}
+
+static int swf_write_header(AVFormatContext *s)
+{
+    SWFContext *swf;
+    PutByteContext *pb = &s->pb;
+    AVEncodeContext *enc = s->video_enc;
+    PutBitContext p;
+    UINT8 buf1[256];
+
+    swf = malloc(sizeof(SWFContext));
+    if (!swf)
+        return -1;
+    s->priv_data = swf;
+
+    put_tag(pb, "FWS");
+    put_byte(pb, 3); /* version (should use 4 for mpeg audio support) */
+    put_le32(pb, DUMMY_FILE_SIZE); /* dummy size 
+                                      (will be patched if not streamed) */ 
+
+    put_swf_rect(pb, 0, enc->width, 0, enc->height);
+    put_le16(pb, enc->rate << 8); /* frame rate */
+    swf->duration_pos = put_pos(pb);
+    put_le16(pb, DUMMY_DURATION * enc->rate); /* frame count */
+    
+    /* define a shape with the jpeg inside */
+
+    put_swf_tag(s, TAG_DEFINESHAPE);
+
+    put_le16(pb, SHAPE_ID); /* ID of shape */
+    /* bounding rectangle */
+    put_swf_rect(pb, 0, enc->width, 0, enc->height);
+    /* style info */
+    put_byte(pb, 1); /* one fill style */
+    put_byte(pb, 0x41); /* clipped bitmap fill */
+    put_le16(pb, BITMAP_ID); /* bitmap ID */
+    /* position of the bitmap */
+    put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0, 
+                   0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
+    put_byte(pb, 0); /* no line style */
+    
+    /* shape drawing */
+    init_put_bits(&p, buf1, sizeof(buf1), NULL, NULL);
+    put_bits(&p, 4, 1); /* one fill bit */
+    put_bits(&p, 4, 0); /* zero line bit */
+    
+    put_bits(&p, 1, 0); /* not an edge */
+    put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
+    put_bits(&p, 5, 1); /* nbits */
+    put_bits(&p, 1, 0); /* X */
+    put_bits(&p, 1, 0); /* Y */
+    put_bits(&p, 1, 1); /* set fill style 1 */
+    
+    /* draw the rectangle ! */
+    put_swf_line_edge(&p, enc->width, 0);
+    put_swf_line_edge(&p, 0, enc->height);
+    put_swf_line_edge(&p, -enc->width, 0);
+    put_swf_line_edge(&p, 0, -enc->height);
+    
+    /* end of shape */
+    put_bits(&p, 1, 0); /* not an edge */
+    put_bits(&p, 5, 0);
+
+    flush_put_bits(&p);
+    put_buffer(pb, buf1, p.buf_ptr - p.buf);
+
+    put_swf_end_tag(s);
+
+    put_flush_packet(&s->pb);
+    return 0;
+}
+
+static int swf_write_video(AVFormatContext *s, UINT8 *buf, int size)
+{
+    PutByteContext *pb = &s->pb;
+    AVEncodeContext *enc = s->video_enc;
+    static int tag_id = 0;
+
+    if (enc->frame_number > 1) {
+        /* remove the shape */
+        put_swf_tag(s, TAG_REMOVEOBJECT);
+        put_le16(pb, SHAPE_ID); /* shape ID */
+        put_le16(pb, 1); /* depth */
+        put_swf_end_tag(s);
+        
+        /* free the bitmap */
+        put_swf_tag(s, TAG_FREECHARACTER);
+        put_le16(pb, BITMAP_ID);
+        put_swf_end_tag(s);
+    }
+
+    put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
+
+    put_le16(pb, tag_id); /* ID of the image */
+
+    /* a dummy jpeg header seems to be required */
+    put_byte(pb, 0xff); 
+    put_byte(pb, 0xd8);
+    put_byte(pb, 0xff);
+    put_byte(pb, 0xd9);
+    /* write the jpeg image */
+    put_buffer(pb, buf, size);
+
+    put_swf_end_tag(s);
+
+    /* draw the shape */
+
+    put_swf_tag(s, TAG_PLACEOBJECT);
+    put_le16(pb, SHAPE_ID); /* shape ID */
+    put_le16(pb, 1); /* depth */
+    put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
+    put_swf_end_tag(s);
+    
+    /* output the frame */
+    put_swf_tag(s, TAG_SHOWFRAME);
+    put_swf_end_tag(s);
+    
+    put_flush_packet(&s->pb);
+    return 0;
+}
+
+static int swf_write_trailer(AVFormatContext *s)
+{
+    SWFContext *swf = s->priv_data;
+    PutByteContext *pb = &s->pb;
+    int file_size;
+    AVEncodeContext *enc = s->video_enc;
+
+    put_swf_tag(s, TAG_END);
+    put_swf_end_tag(s);
+    
+    put_flush_packet(&s->pb);
+
+    /* patch file size and number of frames if not streamed */
+    if (!s->is_streamed) {
+        file_size = put_pos(pb);
+        put_seek(pb, 4, SEEK_SET);
+        put_le32(pb, file_size);
+        put_seek(pb, swf->duration_pos, SEEK_SET);
+        put_le16(pb, enc->frame_number);
+    }
+    free(swf);
+    return 0;
+}
+
+AVFormat swf_format = {
+    "swf",
+    "Flash format",
+    "application/x-shockwave-flash",
+    "swf",
+    CODEC_ID_NONE,
+    CODEC_ID_MJPEG,
+    swf_write_header,
+    NULL,
+    swf_write_video,
+    swf_write_trailer,
+};