/*
- * Animated GIF encoder
- * Copyright (c) 2000 Fabrice Bellard.
+ * Animated GIF muxer
+ * Copyright (c) 2000 Fabrice Bellard
*
- * This library is free software; you can redistribute it and/or
+ * 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 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
*
- * This library is distributed in the hope that it will be useful,
+ * 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 this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
#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 doesn't like it) */
-/* #define GIF_ADD_APP_HEADER */
+/* 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;
/* 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
+ * 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
*/
{ 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;
-
-#ifdef STATS
- st_out_bit_counts[st_current_index] += n;
-#endif
- // 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(ByteIOContext *pb,
- int width, int height, uint32_t *palette)
+static int gif_image_write_header(ByteIOContext *pb,
+ int width, int height, int loop_count,
+ uint32_t *palette)
{
int i;
unsigned int v;
/* the global palette */
if (!palette) {
- put_buffer(pb, (unsigned char *)gif_clut, 216*3);
+ put_buffer(pb, (const unsigned char *)gif_clut, 216*3);
for(i=0;i<((256-216)*3);i++)
put_byte(pb, 0);
} else {
}
}
+ /* 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 */
- /* XXX: not really sure what to put in here... */
#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");
- put_byte(pb, 0x03);
- put_byte(pb, 0x01);
- put_byte(pb, 0x00);
- put_byte(pb, 0x00);
+ 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));
+ return (((r) / 47) % 6) * 6 * 6 + (((g) / 47) % 6) * 6 + (((b) / 47) % 6);
}
-static int gif_image_write_image(ByteIOContext *pb,
+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)
{
w = width;
while(left>0) {
- gif_put_bits_rev(&p, 9, 0x0100); /* clear code */
+ put_bits(&p, 9, 0x0100); /* clear code */
- for(i=0;i<GIF_CHUNKS;i++) {
+ 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);
+ put_bits(&p, 9, v);
if (--w == 0) {
w = width;
buf += linesize;
}
if(left<=GIF_CHUNKS) {
- gif_put_bits_rev(&p, 9, 0x101); /* end of stream */
- gif_flush_put_bits_rev(&p);
+ 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.data_out_size += pbBufPtr(&p) - p.buf;
+ if(put_bits_ptr(&p) - p.buf > 0) {
+ put_byte(pb, put_bits_ptr(&p) - p.buf); /* byte count of the packet */
+ put_buffer(pb, p.buf, put_bits_ptr(&p) - p.buf); /* the actual buffer */
p.buf_ptr = p.buf; /* dequeue the bytes off the bitstream */
}
- if(left<=GIF_CHUNKS) {
- put_byte(pb, 0x00); /* end of image block */
- }
-
left-=GIF_CHUNKS;
}
+ put_byte(pb, 0x00); /* end of image block */
+
return 0;
}
static int gif_write_header(AVFormatContext *s)
{
GIFContext *gif = s->priv_data;
- ByteIOContext *pb = &s->pb;
+ ByteIOContext *pb = s->pb;
AVCodecContext *enc, *video_enc;
- int i, width, height/*, rate*/;
+ int i, width, height, loop_count /*, rate*/;
/* XXX: do we reject audio streams or just ignore them ?
if(s->nb_streams > 1)
video_enc = NULL;
for(i=0;i<s->nb_streams;i++) {
- enc = &s->streams[i]->codec;
+ enc = s->streams[i]->codec;
if (enc->codec_type != CODEC_TYPE_AUDIO)
video_enc = enc;
}
} else {
width = video_enc->width;
height = video_enc->height;
-// rate = video_enc->frame_rate;
+ loop_count = s->loop_output;
+// rate = video_enc->time_base.den;
}
- /* XXX: is it allowed ? seems to work so far... */
- video_enc->pix_fmt = PIX_FMT_RGB24;
+ 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, NULL);
+ gif_image_write_header(pb, width, height, loop_count, NULL);
- put_flush_packet(&s->pb);
+ put_flush_packet(s->pb);
return 0;
}
-static int gif_write_video(AVFormatContext *s,
+static int gif_write_video(AVFormatContext *s,
AVCodecContext *enc, const uint8_t *buf, int size)
{
- ByteIOContext *pb = &s->pb;
+ ByteIOContext *pb = s->pb;
GIFContext *gif = s->priv_data;
int jiffies;
int64_t delay;
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->frame_rate_base/enc->frame_rate) - 1;
+ jiffies = (70*enc->time_base.num/enc->time_base.den) - 1;
put_le16(pb, jiffies);
gif_image_write_image(pb, 0, 0, enc->width, enc->height,
buf, enc->width * 3, PIX_FMT_RGB24);
- put_flush_packet(&s->pb);
+ put_flush_packet(s->pb);
return 0;
}
-static int gif_write_packet(AVFormatContext *s, int stream_index,
- const uint8_t *buf, int size, int64_t pts)
+static int gif_write_packet(AVFormatContext *s, AVPacket *pkt)
{
- AVCodecContext *codec = &s->streams[stream_index]->codec;
+ 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, buf, size);
+ 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;
-}
+ ByteIOContext *pb = s->pb;
-/* better than nothing gif image writer */
-int gif_write(ByteIOContext *pb, AVImageInfo *info)
-{
- gif_image_write_header(pb, info->width, info->height,
- (uint32_t *)info->pict.data[1]);
- gif_image_write_image(pb, 0, 0, info->width, info->height,
- info->pict.data[0], info->pict.linesize[0],
- PIX_FMT_PAL8);
put_byte(pb, 0x3b);
- put_flush_packet(pb);
+ put_flush_packet(s->pb);
return 0;
}
-static AVOutputFormat gif_oformat = {
+AVOutputFormat gif_muxer = {
"gif",
- "GIF Animation",
+ NULL_IF_CONFIG_SMALL("GIF Animation"),
"image/gif",
"gif",
sizeof(GIFContext),
gif_write_packet,
gif_write_trailer,
};
-
-extern AVInputFormat gif_iformat;
-
-int gif_init(void)
-{
- av_register_output_format(&gif_oformat);
- av_register_input_format(&gif_iformat);
- return 0;
-}
projects / ffmpeg / blobdiff