mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
a1b7979261
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
(cherry picked from commit bbc413f943)
359 lines
14 KiB
C
359 lines
14 KiB
C
/*
|
|
* Animated GIF muxer
|
|
* Copyright (c) 2000 Fabrice Bellard
|
|
*
|
|
* 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 "avformat.h"
|
|
|
|
/* The GIF format uses reversed order for bitstreams... */
|
|
/* at least they don't use PDP_ENDIAN :) */
|
|
#define BITSTREAM_WRITER_LE
|
|
|
|
#include "libavcodec/put_bits.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 },
|
|
};
|
|
|
|
/* GIF header */
|
|
static int gif_image_write_header(AVIOContext *pb,
|
|
int width, int height, int loop_count,
|
|
uint32_t *palette)
|
|
{
|
|
int i;
|
|
unsigned int v;
|
|
|
|
avio_write(pb, "GIF", 3);
|
|
avio_write(pb, "89a", 3);
|
|
avio_wl16(pb, width);
|
|
avio_wl16(pb, height);
|
|
|
|
avio_w8(pb, 0xf7); /* flags: global clut, 256 entries */
|
|
avio_w8(pb, 0x1f); /* background color index */
|
|
avio_w8(pb, 0); /* aspect ratio */
|
|
|
|
/* the global palette */
|
|
if (!palette) {
|
|
avio_write(pb, (const unsigned char *)gif_clut, 216*3);
|
|
for(i=0;i<((256-216)*3);i++)
|
|
avio_w8(pb, 0);
|
|
} else {
|
|
for(i=0;i<256;i++) {
|
|
v = palette[i];
|
|
avio_w8(pb, (v >> 16) & 0xff);
|
|
avio_w8(pb, (v >> 8) & 0xff);
|
|
avio_w8(pb, (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) {
|
|
avio_w8(pb, 0x21);
|
|
avio_w8(pb, 0xff);
|
|
avio_w8(pb, 0x0b);
|
|
avio_write(pb, "NETSCAPE2.0", sizeof("NETSCAPE2.0") - 1); // bytes 4 to 14
|
|
avio_w8(pb, 0x03); // byte 15
|
|
avio_w8(pb, 0x01); // byte 16
|
|
avio_wl16(pb, (uint16_t)loop_count);
|
|
avio_w8(pb, 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(AVIOContext *pb,
|
|
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 */
|
|
|
|
avio_w8(pb, 0x2c);
|
|
avio_wl16(pb, x1);
|
|
avio_wl16(pb, y1);
|
|
avio_wl16(pb, width);
|
|
avio_wl16(pb, height);
|
|
avio_w8(pb, 0x00); /* flags */
|
|
/* no local clut */
|
|
|
|
avio_w8(pb, 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) {
|
|
|
|
put_bits(&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++;
|
|
}
|
|
put_bits(&p, 9, v);
|
|
if (--w == 0) {
|
|
w = width;
|
|
buf += linesize;
|
|
ptr = buf;
|
|
}
|
|
}
|
|
|
|
if(left<=GIF_CHUNKS) {
|
|
put_bits(&p, 9, 0x101); /* end of stream */
|
|
flush_put_bits(&p);
|
|
}
|
|
if(put_bits_ptr(&p) - p.buf > 0) {
|
|
avio_w8(pb, put_bits_ptr(&p) - p.buf); /* byte count of the packet */
|
|
avio_write(pb, p.buf, put_bits_ptr(&p) - p.buf); /* the actual buffer */
|
|
p.buf_ptr = p.buf; /* dequeue the bytes off the bitstream */
|
|
}
|
|
left-=GIF_CHUNKS;
|
|
}
|
|
avio_w8(pb, 0x00); /* end of image block */
|
|
|
|
return 0;
|
|
}
|
|
|
|
typedef struct {
|
|
int64_t time, file_time;
|
|
uint8_t buffer[100]; /* data chunks */
|
|
} GIFContext;
|
|
|
|
static int gif_write_header(AVFormatContext *s)
|
|
{
|
|
GIFContext *gif = s->priv_data;
|
|
AVIOContext *pb = s->pb;
|
|
AVCodecContext *enc, *video_enc;
|
|
int i, width, height, loop_count /*, rate*/;
|
|
|
|
/* XXX: do we reject audio streams or just ignore them ?
|
|
if(s->nb_streams > 1)
|
|
return -1;
|
|
*/
|
|
gif->time = 0;
|
|
gif->file_time = 0;
|
|
|
|
video_enc = NULL;
|
|
for(i=0;i<s->nb_streams;i++) {
|
|
enc = s->streams[i]->codec;
|
|
if (enc->codec_type != AVMEDIA_TYPE_AUDIO)
|
|
video_enc = enc;
|
|
}
|
|
|
|
if (!video_enc) {
|
|
av_free(gif);
|
|
return -1;
|
|
} else {
|
|
width = video_enc->width;
|
|
height = video_enc->height;
|
|
loop_count = s->loop_output;
|
|
// rate = video_enc->time_base.den;
|
|
}
|
|
|
|
if (video_enc->pix_fmt != PIX_FMT_RGB24) {
|
|
av_log(s, AV_LOG_ERROR, "ERROR: gif only handles the rgb24 pixel format. Use -pix_fmt rgb24.\n");
|
|
return AVERROR(EIO);
|
|
}
|
|
|
|
gif_image_write_header(pb, width, height, loop_count, NULL);
|
|
|
|
put_flush_packet(s->pb);
|
|
return 0;
|
|
}
|
|
|
|
static int gif_write_video(AVFormatContext *s,
|
|
AVCodecContext *enc, const uint8_t *buf, int size)
|
|
{
|
|
AVIOContext *pb = s->pb;
|
|
GIFContext *gif = s->priv_data;
|
|
int jiffies;
|
|
int64_t delay;
|
|
|
|
/* graphic control extension block */
|
|
avio_w8(pb, 0x21);
|
|
avio_w8(pb, 0xf9);
|
|
avio_w8(pb, 0x04); /* block size */
|
|
avio_w8(pb, 0x04); /* flags */
|
|
|
|
/* 1 jiffy is 1/70 s */
|
|
/* the delay_time field indicates the number of jiffies - 1 */
|
|
delay = gif->file_time - gif->time;
|
|
|
|
/* XXX: should use delay, in order to be more accurate */
|
|
/* instead of using the same rounded value each time */
|
|
/* XXX: don't even remember if I really use it for now */
|
|
jiffies = (70*enc->time_base.num/enc->time_base.den) - 1;
|
|
|
|
avio_wl16(pb, jiffies);
|
|
|
|
avio_w8(pb, 0x1f); /* transparent color index */
|
|
avio_w8(pb, 0x00);
|
|
|
|
gif_image_write_image(pb, 0, 0, enc->width, enc->height,
|
|
buf, enc->width * 3, PIX_FMT_RGB24);
|
|
|
|
put_flush_packet(s->pb);
|
|
return 0;
|
|
}
|
|
|
|
static int gif_write_packet(AVFormatContext *s, AVPacket *pkt)
|
|
{
|
|
AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
|
|
if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
|
|
return 0; /* just ignore audio */
|
|
else
|
|
return gif_write_video(s, codec, pkt->data, pkt->size);
|
|
}
|
|
|
|
static int gif_write_trailer(AVFormatContext *s)
|
|
{
|
|
AVIOContext *pb = s->pb;
|
|
|
|
avio_w8(pb, 0x3b);
|
|
put_flush_packet(s->pb);
|
|
return 0;
|
|
}
|
|
|
|
AVOutputFormat ff_gif_muxer = {
|
|
"gif",
|
|
NULL_IF_CONFIG_SMALL("GIF Animation"),
|
|
"image/gif",
|
|
"gif",
|
|
sizeof(GIFContext),
|
|
CODEC_ID_NONE,
|
|
CODEC_ID_RAWVIDEO,
|
|
gif_write_header,
|
|
gif_write_packet,
|
|
gif_write_trailer,
|
|
};
|