| /* |
| * 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/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 }, |
| }; |
| |
| /* GIF header */ |
| static int gif_image_write_header(ByteIOContext *pb, |
| int width, int height, int loop_count, |
| uint32_t *palette) |
| { |
| int i; |
| unsigned int v; |
| |
| put_tag(pb, "GIF"); |
| put_tag(pb, "89a"); |
| put_le16(pb, width); |
| put_le16(pb, height); |
| |
| put_byte(pb, 0xf7); /* flags: global clut, 256 entries */ |
| put_byte(pb, 0x1f); /* background color index */ |
| put_byte(pb, 0); /* aspect ratio */ |
| |
| /* the global palette */ |
| if (!palette) { |
| put_buffer(pb, (const unsigned char *)gif_clut, 216*3); |
| for(i=0;i<((256-216)*3);i++) |
| put_byte(pb, 0); |
| } else { |
| for(i=0;i<256;i++) { |
| v = palette[i]; |
| put_byte(pb, (v >> 16) & 0xff); |
| put_byte(pb, (v >> 8) & 0xff); |
| put_byte(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) { |
| put_byte(pb, 0x21); |
| put_byte(pb, 0xff); |
| put_byte(pb, 0x0b); |
| put_tag(pb, "NETSCAPE2.0"); // bytes 4 to 14 |
| put_byte(pb, 0x03); // byte 15 |
| put_byte(pb, 0x01); // byte 16 |
| put_le16(pb, (uint16_t)loop_count); |
| put_byte(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(ByteIOContext *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 */ |
| |
| put_byte(pb, 0x2c); |
| put_le16(pb, x1); |
| put_le16(pb, y1); |
| put_le16(pb, width); |
| put_le16(pb, height); |
| put_byte(pb, 0x00); /* flags */ |
| /* no local clut */ |
| |
| put_byte(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(pbBufPtr(&p) - p.buf > 0) { |
| put_byte(pb, pbBufPtr(&p) - p.buf); /* byte count of the packet */ |
| put_buffer(pb, p.buf, pbBufPtr(&p) - p.buf); /* the actual buffer */ |
| p.buf_ptr = p.buf; /* dequeue the bytes off the bitstream */ |
| } |
| left-=GIF_CHUNKS; |
| } |
| put_byte(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; |
| ByteIOContext *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 != CODEC_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) |
| { |
| ByteIOContext *pb = s->pb; |
| GIFContext *gif = s->priv_data; |
| int jiffies; |
| int64_t delay; |
| |
| /* graphic control extension block */ |
| put_byte(pb, 0x21); |
| put_byte(pb, 0xf9); |
| put_byte(pb, 0x04); /* block size */ |
| put_byte(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; |
| |
| put_le16(pb, jiffies); |
| |
| put_byte(pb, 0x1f); /* transparent color index */ |
| put_byte(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 == CODEC_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) |
| { |
| ByteIOContext *pb = s->pb; |
| |
| put_byte(pb, 0x3b); |
| put_flush_packet(s->pb); |
| return 0; |
| } |
| |
| AVOutputFormat 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, |
| }; |
