#include "avcodec.h"
#include "bytestream.h"
+#include "lzw.h"
/* The GIF format uses reversed order for bitstreams... */
/* at least they don't use PDP_ENDIAN :) */
#include "put_bits.h"
-/* bitstream minipacket size */
-#define GIF_CHUNKS 100
+typedef struct {
+ AVFrame picture;
+ LZWState *lzw;
+ uint8_t *buf;
+} GIFContext;
/* GIF header */
-static int gif_image_write_header(uint8_t **bytestream,
- int width, int height,
- uint32_t *palette)
+static int gif_image_write_header(AVCodecContext *avctx,
+ uint8_t **bytestream, uint32_t *palette)
{
int i;
unsigned int v;
bytestream_put_buffer(bytestream, "GIF", 3);
bytestream_put_buffer(bytestream, "89a", 3);
- bytestream_put_le16(bytestream, width);
- bytestream_put_le16(bytestream, height);
+ bytestream_put_le16(bytestream, avctx->width);
+ bytestream_put_le16(bytestream, avctx->height);
bytestream_put_byte(bytestream, 0xf7); /* flags: global clut, 256 entries */
bytestream_put_byte(bytestream, 0x1f); /* background color index */
return 0;
}
-static int gif_image_write_image(uint8_t **bytestream,
- int x1, int y1, int width, int height,
- const uint8_t *buf, int linesize, int pix_fmt)
+static int gif_image_write_image(AVCodecContext *avctx,
+ uint8_t **bytestream, uint8_t *end,
+ const uint8_t *buf, int linesize)
{
- PutBitContext p;
- uint8_t buffer[200]; /* 100 * 9 / 8 = 113 */
- int i, left, w;
+ GIFContext *s = avctx->priv_data;
+ int len, height;
const uint8_t *ptr;
/* image block */
bytestream_put_byte(bytestream, 0x2c);
- bytestream_put_le16(bytestream, x1);
- bytestream_put_le16(bytestream, y1);
- bytestream_put_le16(bytestream, width);
- bytestream_put_le16(bytestream, height);
+ bytestream_put_le16(bytestream, 0);
+ bytestream_put_le16(bytestream, 0);
+ bytestream_put_le16(bytestream, avctx->width);
+ bytestream_put_le16(bytestream, avctx->height);
bytestream_put_byte(bytestream, 0x00); /* flags */
/* no local clut */
bytestream_put_byte(bytestream, 0x08);
- left= width * height;
-
- init_put_bits(&p, buffer, 130);
+ ff_lzw_encode_init(s->lzw, s->buf, avctx->width*avctx->height,
+ 12, FF_LZW_GIF, put_bits);
-/*
- * 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--) {
- put_bits(&p, 9, *ptr++);
- 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) {
- bytestream_put_byte(bytestream, put_bits_ptr(&p) - p.buf); /* byte count of the packet */
- bytestream_put_buffer(bytestream, 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;
+ for (height = avctx->height; height--;) {
+ len += ff_lzw_encode(s->lzw, ptr, avctx->width);
+ ptr += linesize;
+ }
+ len += ff_lzw_encode_flush(s->lzw, flush_put_bits);
+
+ ptr = s->buf;
+ while (len > 0) {
+ int size = FFMIN(255, len);
+ bytestream_put_byte(bytestream, size);
+ if (end - *bytestream < size)
+ return -1;
+ bytestream_put_buffer(bytestream, ptr, size);
+ ptr += size;
+ len -= size;
}
bytestream_put_byte(bytestream, 0x00); /* end of image block */
bytestream_put_byte(bytestream, 0x3b);
return 0;
}
-typedef struct {
- AVFrame picture;
-} GIFContext;
-
static av_cold int gif_encode_init(AVCodecContext *avctx)
{
GIFContext *s = avctx->priv_data;
avctx->coded_frame = &s->picture;
+ s->lzw = av_mallocz(ff_lzw_encode_state_size);
+ if (!s->lzw)
+ return AVERROR(ENOMEM);
+ s->buf = av_malloc(avctx->width*avctx->height*2);
+ if (!s->buf)
+ return AVERROR(ENOMEM);
return 0;
}
AVFrame *pict = data;
AVFrame *const p = (AVFrame *)&s->picture;
uint8_t *outbuf_ptr = outbuf;
+ uint8_t *end = outbuf + buf_size;
*p = *pict;
p->pict_type = FF_I_TYPE;
p->key_frame = 1;
- gif_image_write_header(&outbuf_ptr, avctx->width, avctx->height, (uint32_t *)pict->data[1]);
- gif_image_write_image(&outbuf_ptr, 0, 0, avctx->width, avctx->height, pict->data[0], pict->linesize[0], PIX_FMT_PAL8);
+ gif_image_write_header(avctx, &outbuf_ptr, (uint32_t *)pict->data[1]);
+ gif_image_write_image(avctx, &outbuf_ptr, end, pict->data[0], pict->linesize[0]);
return outbuf_ptr - outbuf;
}
+static int gif_encode_close(AVCodecContext *avctx)
+{
+ GIFContext *s = avctx->priv_data;
+
+ av_freep(&s->lzw);
+ av_freep(&s->buf);
+ return 0;
+}
+
AVCodec gif_encoder = {
"gif",
- CODEC_TYPE_VIDEO,
+ AVMEDIA_TYPE_VIDEO,
CODEC_ID_GIF,
sizeof(GIFContext),
gif_encode_init,
gif_encode_frame,
- NULL, //encode_end,
- .pix_fmts= (enum PixelFormat[]){PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8, PIX_FMT_NONE},
+ gif_encode_close,
+ .pix_fmts= (const enum PixelFormat[]){PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8, PIX_FMT_NONE},
.long_name= NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"),
};
projects / ffmpeg / blobdiff