change gif muxer to simple gif encoder

Originally committed as revision 6874 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 350 insertions, 0 deletions

diff --git a/libavcodec/gif.c b/libavcodec/gif.c
new file mode 100644
index 0000000000..f67ab52c22
--- /dev/null
+++ b/libavcodec/gif.c
@@ -0,0 +1,350 @@
+/*
+ * GIF encoder.
+ * Copyright (c) 2000 Fabrice Bellard.
+ * Copyright (c) 2002 Francois Revol.
+ * Copyright (c) 2006 Baptiste Coudurier.
+ *
+ * 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
+ */
+
+/*
+ * First version by Francois Revol revol@free.fr
+ *
+ * Features and limitations:
+ * - currently no compression is performed,
+ *   in fact the size of the data is 9/8 the size of the image in 8bpp
+ * - uses only a global standard palette
+ * - tested with IE 5.0, Opera for BeOS, NetPositive (BeOS), and Mozilla (BeOS).
+ *
+ * Reference documents:
+ * http://www.goice.co.jp/member/mo/formats/gif.html
+ * http://astronomy.swin.edu.au/pbourke/dataformats/gif/
+ * http://www.dcs.ed.ac.uk/home/mxr/gfx/2d/GIF89a.txt
+ *
+ * this url claims to have an LZW algorithm not covered by Unisys patent:
+ * http://www.msg.net/utility/whirlgif/gifencod.html
+ * could help reduce the size of the files _a lot_...
+ * some sites mentions an RLE type compression also.
+ */
+
+#include "avcodec.h"
+#include "bytestream.h"
+#include "bitstream.h"
+
+/* bitstream minipacket size */
+#define GIF_CHUNKS 100
+
+/* slows down the decoding (and some browsers don't like it) */
+/* update on the 'some browsers don't like it issue from above: this was probably due to missing 'Data Sub-block Terminator' (byte 19) in the app_header */
+#define GIF_ADD_APP_HEADER // required to enable looping of animated gif
+
+typedef struct {
+    unsigned char r;
+    unsigned char g;
+    unsigned char b;
+} rgb_triplet;
+
+/* we use the standard 216 color palette */
+
+/* this script was used to create the palette:
+ * for r in 00 33 66 99 cc ff; do for g in 00 33 66 99 cc ff; do echo -n "    "; for b in 00 33 66 99 cc ff; do
+ *   echo -n "{ 0x$r, 0x$g, 0x$b }, "; done; echo ""; done; done
+ */
+
+static const rgb_triplet gif_clut[216] = {
+    { 0x00, 0x00, 0x00 }, { 0x00, 0x00, 0x33 }, { 0x00, 0x00, 0x66 }, { 0x00, 0x00, 0x99 }, { 0x00, 0x00, 0xcc }, { 0x00, 0x00, 0xff },
+    { 0x00, 0x33, 0x00 }, { 0x00, 0x33, 0x33 }, { 0x00, 0x33, 0x66 }, { 0x00, 0x33, 0x99 }, { 0x00, 0x33, 0xcc }, { 0x00, 0x33, 0xff },
+    { 0x00, 0x66, 0x00 }, { 0x00, 0x66, 0x33 }, { 0x00, 0x66, 0x66 }, { 0x00, 0x66, 0x99 }, { 0x00, 0x66, 0xcc }, { 0x00, 0x66, 0xff },
+    { 0x00, 0x99, 0x00 }, { 0x00, 0x99, 0x33 }, { 0x00, 0x99, 0x66 }, { 0x00, 0x99, 0x99 }, { 0x00, 0x99, 0xcc }, { 0x00, 0x99, 0xff },
+    { 0x00, 0xcc, 0x00 }, { 0x00, 0xcc, 0x33 }, { 0x00, 0xcc, 0x66 }, { 0x00, 0xcc, 0x99 }, { 0x00, 0xcc, 0xcc }, { 0x00, 0xcc, 0xff },
+    { 0x00, 0xff, 0x00 }, { 0x00, 0xff, 0x33 }, { 0x00, 0xff, 0x66 }, { 0x00, 0xff, 0x99 }, { 0x00, 0xff, 0xcc }, { 0x00, 0xff, 0xff },
+    { 0x33, 0x00, 0x00 }, { 0x33, 0x00, 0x33 }, { 0x33, 0x00, 0x66 }, { 0x33, 0x00, 0x99 }, { 0x33, 0x00, 0xcc }, { 0x33, 0x00, 0xff },
+    { 0x33, 0x33, 0x00 }, { 0x33, 0x33, 0x33 }, { 0x33, 0x33, 0x66 }, { 0x33, 0x33, 0x99 }, { 0x33, 0x33, 0xcc }, { 0x33, 0x33, 0xff },
+    { 0x33, 0x66, 0x00 }, { 0x33, 0x66, 0x33 }, { 0x33, 0x66, 0x66 }, { 0x33, 0x66, 0x99 }, { 0x33, 0x66, 0xcc }, { 0x33, 0x66, 0xff },
+    { 0x33, 0x99, 0x00 }, { 0x33, 0x99, 0x33 }, { 0x33, 0x99, 0x66 }, { 0x33, 0x99, 0x99 }, { 0x33, 0x99, 0xcc }, { 0x33, 0x99, 0xff },
+    { 0x33, 0xcc, 0x00 }, { 0x33, 0xcc, 0x33 }, { 0x33, 0xcc, 0x66 }, { 0x33, 0xcc, 0x99 }, { 0x33, 0xcc, 0xcc }, { 0x33, 0xcc, 0xff },
+    { 0x33, 0xff, 0x00 }, { 0x33, 0xff, 0x33 }, { 0x33, 0xff, 0x66 }, { 0x33, 0xff, 0x99 }, { 0x33, 0xff, 0xcc }, { 0x33, 0xff, 0xff },
+    { 0x66, 0x00, 0x00 }, { 0x66, 0x00, 0x33 }, { 0x66, 0x00, 0x66 }, { 0x66, 0x00, 0x99 }, { 0x66, 0x00, 0xcc }, { 0x66, 0x00, 0xff },
+    { 0x66, 0x33, 0x00 }, { 0x66, 0x33, 0x33 }, { 0x66, 0x33, 0x66 }, { 0x66, 0x33, 0x99 }, { 0x66, 0x33, 0xcc }, { 0x66, 0x33, 0xff },
+    { 0x66, 0x66, 0x00 }, { 0x66, 0x66, 0x33 }, { 0x66, 0x66, 0x66 }, { 0x66, 0x66, 0x99 }, { 0x66, 0x66, 0xcc }, { 0x66, 0x66, 0xff },
+    { 0x66, 0x99, 0x00 }, { 0x66, 0x99, 0x33 }, { 0x66, 0x99, 0x66 }, { 0x66, 0x99, 0x99 }, { 0x66, 0x99, 0xcc }, { 0x66, 0x99, 0xff },
+    { 0x66, 0xcc, 0x00 }, { 0x66, 0xcc, 0x33 }, { 0x66, 0xcc, 0x66 }, { 0x66, 0xcc, 0x99 }, { 0x66, 0xcc, 0xcc }, { 0x66, 0xcc, 0xff },
+    { 0x66, 0xff, 0x00 }, { 0x66, 0xff, 0x33 }, { 0x66, 0xff, 0x66 }, { 0x66, 0xff, 0x99 }, { 0x66, 0xff, 0xcc }, { 0x66, 0xff, 0xff },
+    { 0x99, 0x00, 0x00 }, { 0x99, 0x00, 0x33 }, { 0x99, 0x00, 0x66 }, { 0x99, 0x00, 0x99 }, { 0x99, 0x00, 0xcc }, { 0x99, 0x00, 0xff },
+    { 0x99, 0x33, 0x00 }, { 0x99, 0x33, 0x33 }, { 0x99, 0x33, 0x66 }, { 0x99, 0x33, 0x99 }, { 0x99, 0x33, 0xcc }, { 0x99, 0x33, 0xff },
+    { 0x99, 0x66, 0x00 }, { 0x99, 0x66, 0x33 }, { 0x99, 0x66, 0x66 }, { 0x99, 0x66, 0x99 }, { 0x99, 0x66, 0xcc }, { 0x99, 0x66, 0xff },
+    { 0x99, 0x99, 0x00 }, { 0x99, 0x99, 0x33 }, { 0x99, 0x99, 0x66 }, { 0x99, 0x99, 0x99 }, { 0x99, 0x99, 0xcc }, { 0x99, 0x99, 0xff },
+    { 0x99, 0xcc, 0x00 }, { 0x99, 0xcc, 0x33 }, { 0x99, 0xcc, 0x66 }, { 0x99, 0xcc, 0x99 }, { 0x99, 0xcc, 0xcc }, { 0x99, 0xcc, 0xff },
+    { 0x99, 0xff, 0x00 }, { 0x99, 0xff, 0x33 }, { 0x99, 0xff, 0x66 }, { 0x99, 0xff, 0x99 }, { 0x99, 0xff, 0xcc }, { 0x99, 0xff, 0xff },
+    { 0xcc, 0x00, 0x00 }, { 0xcc, 0x00, 0x33 }, { 0xcc, 0x00, 0x66 }, { 0xcc, 0x00, 0x99 }, { 0xcc, 0x00, 0xcc }, { 0xcc, 0x00, 0xff },
+    { 0xcc, 0x33, 0x00 }, { 0xcc, 0x33, 0x33 }, { 0xcc, 0x33, 0x66 }, { 0xcc, 0x33, 0x99 }, { 0xcc, 0x33, 0xcc }, { 0xcc, 0x33, 0xff },
+    { 0xcc, 0x66, 0x00 }, { 0xcc, 0x66, 0x33 }, { 0xcc, 0x66, 0x66 }, { 0xcc, 0x66, 0x99 }, { 0xcc, 0x66, 0xcc }, { 0xcc, 0x66, 0xff },
+    { 0xcc, 0x99, 0x00 }, { 0xcc, 0x99, 0x33 }, { 0xcc, 0x99, 0x66 }, { 0xcc, 0x99, 0x99 }, { 0xcc, 0x99, 0xcc }, { 0xcc, 0x99, 0xff },
+    { 0xcc, 0xcc, 0x00 }, { 0xcc, 0xcc, 0x33 }, { 0xcc, 0xcc, 0x66 }, { 0xcc, 0xcc, 0x99 }, { 0xcc, 0xcc, 0xcc }, { 0xcc, 0xcc, 0xff },
+    { 0xcc, 0xff, 0x00 }, { 0xcc, 0xff, 0x33 }, { 0xcc, 0xff, 0x66 }, { 0xcc, 0xff, 0x99 }, { 0xcc, 0xff, 0xcc }, { 0xcc, 0xff, 0xff },
+    { 0xff, 0x00, 0x00 }, { 0xff, 0x00, 0x33 }, { 0xff, 0x00, 0x66 }, { 0xff, 0x00, 0x99 }, { 0xff, 0x00, 0xcc }, { 0xff, 0x00, 0xff },
+    { 0xff, 0x33, 0x00 }, { 0xff, 0x33, 0x33 }, { 0xff, 0x33, 0x66 }, { 0xff, 0x33, 0x99 }, { 0xff, 0x33, 0xcc }, { 0xff, 0x33, 0xff },
+    { 0xff, 0x66, 0x00 }, { 0xff, 0x66, 0x33 }, { 0xff, 0x66, 0x66 }, { 0xff, 0x66, 0x99 }, { 0xff, 0x66, 0xcc }, { 0xff, 0x66, 0xff },
+    { 0xff, 0x99, 0x00 }, { 0xff, 0x99, 0x33 }, { 0xff, 0x99, 0x66 }, { 0xff, 0x99, 0x99 }, { 0xff, 0x99, 0xcc }, { 0xff, 0x99, 0xff },
+    { 0xff, 0xcc, 0x00 }, { 0xff, 0xcc, 0x33 }, { 0xff, 0xcc, 0x66 }, { 0xff, 0xcc, 0x99 }, { 0xff, 0xcc, 0xcc }, { 0xff, 0xcc, 0xff },
+    { 0xff, 0xff, 0x00 }, { 0xff, 0xff, 0x33 }, { 0xff, 0xff, 0x66 }, { 0xff, 0xff, 0x99 }, { 0xff, 0xff, 0xcc }, { 0xff, 0xff, 0xff },
+};
+
+/* The GIF format uses reversed order for bitstreams... */
+/* at least they don't use PDP_ENDIAN :) */
+/* so we 'extend' PutBitContext. hmmm, OOP :) */
+/* seems this thing changed slightly since I wrote it... */
+
+#ifdef ALT_BITSTREAM_WRITER
+# error no ALT_BITSTREAM_WRITER support for now
+#endif
+
+static void gif_put_bits_rev(PutBitContext *s, int n, unsigned int value)
+{
+    unsigned int bit_buf;
+    int bit_cnt;
+
+    //    printf("put_bits=%d %x\n", n, value);
+    assert(n == 32 || value < (1U << n));
+
+    bit_buf = s->bit_buf;
+    bit_cnt = 32 - s->bit_left; /* XXX:lazyness... was = s->bit_cnt; */
+
+    //    printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf);
+    /* XXX: optimize */
+    if (n < (32-bit_cnt)) {
+        bit_buf |= value << (bit_cnt);
+        bit_cnt+=n;
+    } else {
+        bit_buf |= value << (bit_cnt);
+
+        *s->buf_ptr = bit_buf & 0xff;
+        s->buf_ptr[1] = (bit_buf >> 8) & 0xff;
+        s->buf_ptr[2] = (bit_buf >> 16) & 0xff;
+        s->buf_ptr[3] = (bit_buf >> 24) & 0xff;
+
+        //printf("bitbuf = %08x\n", bit_buf);
+        s->buf_ptr+=4;
+        if (s->buf_ptr >= s->buf_end)
+            puts("bit buffer overflow !!"); // should never happen ! who got rid of the callback ???
+//            flush_buffer_rev(s);
+        bit_cnt=bit_cnt + n - 32;
+        if (bit_cnt == 0) {
+            bit_buf = 0;
+        } else {
+            bit_buf = value >> (n - bit_cnt);
+        }
+    }
+
+    s->bit_buf = bit_buf;
+    s->bit_left = 32 - bit_cnt;
+}
+
+/* pad the end of the output stream with zeros */
+static void gif_flush_put_bits_rev(PutBitContext *s)
+{
+    while (s->bit_left < 32) {
+        /* XXX: should test end of buffer */
+        *s->buf_ptr++=s->bit_buf & 0xff;
+        s->bit_buf>>=8;
+        s->bit_left+=8;
+    }
+//    flush_buffer_rev(s);
+    s->bit_left=32;
+    s->bit_buf=0;
+}
+
+/* !RevPutBitContext */
+
+/* GIF header */
+static int gif_image_write_header(uint8_t **bytestream,
+                                  int width, int height, int loop_count,
+                                  uint32_t *palette)
+{
+    int i;
+    unsigned int v;
+
+    bytestream_put_buffer(bytestream, "GIF", 3);
+    bytestream_put_buffer(bytestream, "89a", 3);
+    bytestream_put_le16(bytestream, width);
+    bytestream_put_le16(bytestream, height);
+
+    bytestream_put_byte(bytestream, 0xf7); /* flags: global clut, 256 entries */
+    bytestream_put_byte(bytestream, 0x1f); /* background color index */
+    bytestream_put_byte(bytestream, 0); /* aspect ratio */
+
+    /* the global palette */
+    if (!palette) {
+        bytestream_put_buffer(bytestream, (const unsigned char *)gif_clut, 216*3);
+        for(i=0;i<((256-216)*3);i++)
+            bytestream_put_byte(bytestream, 0);
+    } else {
+        for(i=0;i<256;i++) {
+            v = palette[i];
+            bytestream_put_byte(bytestream, (v >> 16) & 0xff);
+            bytestream_put_byte(bytestream, (v >> 8) & 0xff);
+            bytestream_put_byte(bytestream, (v) & 0xff);
+        }
+    }
+
+        /*        update: this is the 'NETSCAPE EXTENSION' that allows for looped animated gif
+                see http://members.aol.com/royalef/gifabout.htm#net-extension
+
+                byte   1       : 33 (hex 0x21) GIF Extension code
+                byte   2       : 255 (hex 0xFF) Application Extension Label
+                byte   3       : 11 (hex (0x0B) Length of Application Block
+                                         (eleven bytes of data to follow)
+                bytes  4 to 11 : "NETSCAPE"
+                bytes 12 to 14 : "2.0"
+                byte  15       : 3 (hex 0x03) Length of Data Sub-Block
+                                         (three bytes of data to follow)
+                byte  16       : 1 (hex 0x01)
+                bytes 17 to 18 : 0 to 65535, an unsigned integer in
+                                         lo-hi byte format. This indicate the
+                                         number of iterations the loop should
+                                         be executed.
+                bytes 19       : 0 (hex 0x00) a Data Sub-block Terminator
+        */
+
+    /* application extension header */
+#ifdef GIF_ADD_APP_HEADER
+    if (loop_count >= 0 && loop_count <= 65535) {
+        bytestream_put_byte(bytestream, 0x21);
+        bytestream_put_byte(bytestream, 0xff);
+        bytestream_put_byte(bytestream, 0x0b);
+        bytestream_put_buffer(bytestream, "NETSCAPE2.0", 11);  // bytes 4 to 14
+        bytestream_put_byte(bytestream, 0x03); // byte 15
+        bytestream_put_byte(bytestream, 0x01); // byte 16
+        bytestream_put_le16(bytestream, (uint16_t)loop_count);
+        bytestream_put_byte(bytestream, 0x00); // byte 19
+    }
+#endif
+    return 0;
+}
+
+/* this is maybe slow, but allows for extensions */
+static inline unsigned char gif_clut_index(uint8_t r, uint8_t g, uint8_t b)
+{
+    return ((((r)/47)%6)*6*6+(((g)/47)%6)*6+(((b)/47)%6));
+}
+
+
+static int gif_image_write_image(uint8_t **bytestream,
+                                 int x1, int y1, int width, int height,
+                                 const uint8_t *buf, int linesize, int pix_fmt)
+{
+    PutBitContext p;
+    uint8_t buffer[200]; /* 100 * 9 / 8 = 113 */
+    int i, left, w, v;
+    const uint8_t *ptr;
+    /* image block */
+
+    bytestream_put_byte(bytestream, 0x2c);
+    bytestream_put_le16(bytestream, x1);
+    bytestream_put_le16(bytestream, y1);
+    bytestream_put_le16(bytestream, width);
+    bytestream_put_le16(bytestream, height);
+    bytestream_put_byte(bytestream, 0x00); /* flags */
+    /* no local clut */
+
+    bytestream_put_byte(bytestream, 0x08);
+
+    left= width * height;
+
+    init_put_bits(&p, buffer, 130);
+
+/*
+ * the thing here is the bitstream is written as little packets, with a size byte before
+ * but it's still the same bitstream between packets (no flush !)
+ */
+    ptr = buf;
+    w = width;
+    while(left>0) {
+
+        gif_put_bits_rev(&p, 9, 0x0100); /* clear code */
+
+        for(i=(left<GIF_CHUNKS)?left:GIF_CHUNKS;i;i--) {
+            if (pix_fmt == PIX_FMT_RGB24) {
+                v = gif_clut_index(ptr[0], ptr[1], ptr[2]);
+                ptr+=3;
+            } else {
+                v = *ptr++;
+            }
+            gif_put_bits_rev(&p, 9, v);
+            if (--w == 0) {
+                w = width;
+                buf += linesize;
+                ptr = buf;
+            }
+        }
+
+        if(left<=GIF_CHUNKS) {
+            gif_put_bits_rev(&p, 9, 0x101); /* end of stream */
+            gif_flush_put_bits_rev(&p);
+        }
+        if(pbBufPtr(&p) - p.buf > 0) {
+            bytestream_put_byte(bytestream, pbBufPtr(&p) - p.buf); /* byte count of the packet */
+            bytestream_put_buffer(bytestream, p.buf, pbBufPtr(&p) - p.buf); /* the actual buffer */
+            p.buf_ptr = p.buf; /* dequeue the bytes off the bitstream */
+        }
+        left-=GIF_CHUNKS;
+    }
+    bytestream_put_byte(bytestream, 0x00); /* end of image block */
+    bytestream_put_byte(bytestream, 0x3b);
+    return 0;
+}
+
+typedef struct {
+    int64_t time, file_time;
+    uint8_t buffer[100]; /* data chunks */
+    AVFrame picture;
+} GIFContext;
+
+static int gif_encode_init(AVCodecContext *avctx)
+{
+    GIFContext *s = avctx->priv_data;
+
+    avctx->coded_frame = &s->picture;
+    return 0;
+}
+
+/* better than nothing gif encoder */
+static int gif_encode_frame(AVCodecContext *avctx, unsigned char *outbuf, int buf_size, void *data)
+{
+    GIFContext *s = avctx->priv_data;
+    AVFrame *pict = data;
+    AVFrame *const p = (AVFrame *)&s->picture;
+    uint8_t *outbuf_ptr = outbuf;
+
+    *p = *pict;
+    p->pict_type = FF_I_TYPE;
+    p->key_frame = 1;
+    gif_image_write_header(&outbuf_ptr, avctx->width, avctx->height, -1, (uint32_t *)pict->data[1]);
+    gif_image_write_image(&outbuf_ptr, 0, 0, avctx->width, avctx->height, pict->data[0], pict->linesize[0], PIX_FMT_PAL8);
+    return outbuf_ptr - outbuf;
+}
+
+AVCodec gif_encoder = {
+    "gif",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_GIF,
+    sizeof(GIFContext),
+    gif_encode_init,
+    gif_encode_frame,
+    NULL, //encode_end,
+    .pix_fmts= (enum PixelFormat[]){PIX_FMT_PAL8, -1},
+};