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added primitive image GIF encoder based on animated gif encoder

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Originally committed as revision 1540 to svn://svn.ffmpeg.org/ffmpeg/trunk
pull/126/head
Fabrice Bellard 22 years ago
parent fcfa89e81c
commit ba19f84810
1 changed files with 121 additions and 85 deletions
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  1. 206
      libavformat/gif.c

206
libavformat/gif.c
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@ -166,45 +166,10 @@ static void gif_flush_put_bits_rev(PutBitContext *s)
/* !RevPutBitContext */
typedef struct {
UINT8 buffer[100]; /* data chunks */
INT64 time, file_time;
} GIFContext;
static int gif_write_header(AVFormatContext *s)
/* GIF header */
static int gif_image_write_header(ByteIOContext *pb, int width, int height)
{
GIFContext *gif = s->priv_data;
ByteIOContext *pb = &s->pb;
AVCodecContext *enc, *video_enc;
int i, width, height, 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;
rate = video_enc->frame_rate;
}
/* XXX: is it allowed ? seems to work so far... */
video_enc->pix_fmt = PIX_FMT_RGB24;
/* GIF header */
int i;
put_tag(pb, "GIF");
put_tag(pb, "89a");
@ -233,8 +198,6 @@ static int gif_write_header(AVFormatContext *s)
put_byte(pb, 0x00);
put_byte(pb, 0x00);
#endif
put_flush_packet(&s->pb);
return 0;
}
@ -244,60 +207,28 @@ static inline unsigned char gif_clut_index(rgb_triplet *clut, UINT8 r, UINT8 g,
return ((((r)/47)%6)*6*6+(((g)/47)%6)*6+(((b)/47)%6));
}
/* chunk writer callback */
/* !!! XXX:deprecated
static void gif_put_chunk(void *pbctx, UINT8 *buffer, int count)
{
ByteIOContext *pb = (ByteIOContext *)pbctx;
put_byte(pb, (UINT8)count);
put_buffer(pb, buffer, count);
}
*/
static int gif_write_video(AVFormatContext *s,
AVCodecContext *enc, UINT8 *buf, int size)
static int gif_image_write_image(ByteIOContext *pb,
int x1, int y1, int width, int height,
uint8_t *buf, int linesize)
{
ByteIOContext *pb = &s->pb;
GIFContext *gif = s->priv_data;
int i, left, jiffies;
INT64 delay;
PutBitContext p;
UINT8 buffer[200]; /* 100 * 9 / 8 = 113 */
/* 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*FRAME_RATE_BASE/enc->frame_rate) - 1;
put_le16(pb, jiffies);
put_byte(pb, 0x1f); /* transparent color index */
put_byte(pb, 0x00);
int i, left, w;
uint8_t *ptr;
/* image block */
put_byte(pb, 0x2c);
put_le16(pb, 0);
put_le16(pb, 0);
put_le16(pb, enc->width);
put_le16(pb, enc->height);
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=size/3;
left= width * height;
init_put_bits(&p, buffer, 130, NULL, NULL);
@ -305,14 +236,20 @@ static int gif_write_video(AVFormatContext *s,
* 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=0;i<GIF_CHUNKS;i++) {
gif_put_bits_rev(&p, 9, gif_clut_index(NULL, *buf, buf[1], buf[2]));
buf+=3;
gif_put_bits_rev(&p, 9, gif_clut_index(NULL, ptr[0], ptr[1], ptr[2]));
ptr+=3;
if (--w == 0) {
w = width;
buf += linesize;
ptr = buf;
}
}
if(left<=GIF_CHUNKS) {
@ -331,6 +268,93 @@ static int gif_write_video(AVFormatContext *s,
left-=GIF_CHUNKS;
}
return 0;
}
typedef struct {
INT64 time, file_time;
UINT8 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, 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;
rate = video_enc->frame_rate;
}
/* XXX: is it allowed ? seems to work so far... */
video_enc->pix_fmt = PIX_FMT_RGB24;
gif_image_write_header(pb, width, height);
put_flush_packet(&s->pb);
return 0;
}
/* chunk writer callback */
/* !!! XXX:deprecated
static void gif_put_chunk(void *pbctx, UINT8 *buffer, int count)
{
ByteIOContext *pb = (ByteIOContext *)pbctx;
put_byte(pb, (UINT8)count);
put_buffer(pb, buffer, count);
}
*/
static int gif_write_video(AVFormatContext *s,
AVCodecContext *enc, UINT8 *buf, int size)
{
ByteIOContext *pb = &s->pb;
GIFContext *gif = s->priv_data;
int jiffies;
INT64 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*FRAME_RATE_BASE/enc->frame_rate) - 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);
put_flush_packet(&s->pb);
return 0;
@ -355,6 +379,17 @@ static int gif_write_trailer(AVFormatContext *s)
return 0;
}
/* better than nothing gif image writer */
int gif_write(ByteIOContext *pb, AVImageInfo *info)
{
gif_image_write_header(pb, info->width, info->height);
gif_image_write_image(pb, 0, 0, info->width, info->height,
info->pict.data[0], info->pict.linesize[0]);
put_byte(pb, 0x3b);
put_flush_packet(pb);
return 0;
}
static AVOutputFormat gif_oformat = {
"gif",
"GIF Animation",
@ -367,6 +402,7 @@ static AVOutputFormat gif_oformat = {
gif_write_packet,
gif_write_trailer,
};
extern AVInputFormat gif_iformat;
int gif_init(void)

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