*/
#include "avformat.h"
+#include "bitstream.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;
/* !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, int loop_count,
+ uint32_t *palette)
{
- 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;
+ unsigned int v;
put_tag(pb, "GIF");
put_tag(pb, "89a");
put_byte(pb, 0); /* aspect ratio */
/* the global palette */
+ if (!palette) {
+ put_buffer(pb, (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);
+ }
+ }
- put_buffer(pb, (unsigned char *)gif_clut, 216*3);
- for(i=0;i<((256-216)*3);i++)
- put_byte(pb, 0);
+ /* 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
-
- put_flush_packet(&s->pb);
return 0;
}
/* this is maybe slow, but allows for extensions */
-static inline unsigned char gif_clut_index(rgb_triplet *clut, UINT8 r, UINT8 g, UINT8 b)
+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));
}
-/* 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,
+ const uint8_t *buf, int linesize, int pix_fmt)
{
- 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);
-
+ 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, 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);
+ 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=0;i<GIF_CHUNKS;i++) {
- gif_put_bits_rev(&p, 9, gif_clut_index(NULL, *buf, buf[1], buf[2]));
- buf+=3;
+ 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) {
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;
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;
+}
+
+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;
+ }
+
+ /* XXX: is it allowed ? seems to work so far... */
+ video_enc->pix_fmt = PIX_FMT_RGB24;
+
+ 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, int stream_index,
- UINT8 *buf, int size, int force_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)
return 0;
}
+/* better than nothing gif image writer */
+int gif_write(ByteIOContext *pb, AVImageInfo *info)
+{
+ gif_image_write_header(pb, info->width, info->height, AVFMT_NOOUTPUTLOOP,
+ (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);
+ return 0;
+}
+
static AVOutputFormat gif_oformat = {
"gif",
"GIF Animation",
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