/*
* GIF decoder
- * Copyright (c) 2003 Fabrice Bellard.
- * Copyright (c) 2006 Baptiste Coudurier.
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2006 Baptiste Coudurier
*
* This file is part of FFmpeg.
*
int gce_delay;
/* LZW compatible decoder */
- uint8_t *bytestream;
+ const uint8_t *bytestream;
+ const uint8_t *bytestream_end;
LZWState *lzw;
/* aux buffers */
uint8_t global_palette[256 * 3];
uint8_t local_palette[256 * 3];
+
+ AVCodecContext* avctx;
} GifState;
static const uint8_t gif87a_sig[6] = "GIF87a";
{
int left, top, width, height, bits_per_pixel, code_size, flags;
int is_interleaved, has_local_palette, y, pass, y1, linesize, n, i;
- uint8_t *ptr, *line, *spal, *palette, *ptr1;
+ uint8_t *ptr, *spal, *palette, *ptr1;
left = bytestream_get_le16(&s->bytestream);
top = bytestream_get_le16(&s->bytestream);
has_local_palette = flags & 0x80;
bits_per_pixel = (flags & 0x07) + 1;
#ifdef DEBUG
- dprintf("gif: image x=%d y=%d w=%d h=%d\n", left, top, width, height);
+ dprintf(s->avctx, "gif: image x=%d y=%d w=%d h=%d\n", left, top, width, height);
#endif
if (has_local_palette) {
/* verify that all the image is inside the screen dimensions */
if (left + width > s->screen_width ||
top + height > s->screen_height)
- return -EINVAL;
+ return AVERROR(EINVAL);
/* build the palette */
n = (1 << bits_per_pixel);
spal = palette;
for(i = 0; i < n; i++) {
- s->image_palette[i] = (0xff << 24) |
- (spal[0] << 16) | (spal[1] << 8) | (spal[2]);
+ s->image_palette[i] = (0xff << 24) | AV_RB24(spal);
spal += 3;
}
for(; i < 256; i++)
/* handle transparency */
if (s->transparent_color_index >= 0)
s->image_palette[s->transparent_color_index] = 0;
- line = NULL;
/* now get the image data */
code_size = bytestream_get_byte(&s->bytestream);
- //TODO: add proper data size
- ff_lzw_decode_init(s->lzw, code_size, s->bytestream, 0, FF_LZW_GIF);
+ ff_lzw_decode_init(s->lzw, code_size, s->bytestream,
+ s->bytestream_end - s->bytestream, FF_LZW_GIF);
/* read all the image */
linesize = s->picture.linesize[0];
- ptr1 = s->picture.data[0] + top * linesize + (left * 3);
+ ptr1 = s->picture.data[0] + top * linesize + left;
ptr = ptr1;
pass = 0;
y1 = 0;
y1 += 8;
ptr += linesize * 8;
if (y1 >= height) {
- y1 = 4;
- if (pass == 0)
- ptr = ptr1 + linesize * 4;
- else
- ptr = ptr1 + linesize * 2;
+ y1 = pass ? 2 : 4;
+ ptr = ptr1 + linesize * y1;
pass++;
}
break;
ptr += linesize;
}
}
- av_free(line);
-
/* read the garbage data until end marker is found */
ff_lzw_decode_tail(s->lzw);
s->bytestream = ff_lzw_cur_ptr(s->lzw);
ext_code = bytestream_get_byte(&s->bytestream);
ext_len = bytestream_get_byte(&s->bytestream);
#ifdef DEBUG
- dprintf("gif: ext_code=0x%x len=%d\n", ext_code, ext_len);
+ dprintf(s->avctx, "gif: ext_code=0x%x len=%d\n", ext_code, ext_len);
#endif
switch(ext_code) {
case 0xf9:
s->transparent_color_index = -1;
s->gce_disposal = (gce_flags >> 2) & 0x7;
#ifdef DEBUG
- dprintf("gif: gce_flags=%x delay=%d tcolor=%d disposal=%d\n",
+ dprintf(s->avctx, "gif: gce_flags=%x delay=%d tcolor=%d disposal=%d\n",
gce_flags, s->gce_delay,
s->transparent_color_index, s->gce_disposal);
#endif
bytestream_get_byte(&s->bytestream);
ext_len = bytestream_get_byte(&s->bytestream);
#ifdef DEBUG
- dprintf("gif: ext_len1=%d\n", ext_len);
+ dprintf(s->avctx, "gif: ext_len1=%d\n", ext_len);
#endif
}
return 0;
int v, n;
int has_global_palette;
+ if (s->bytestream_end < s->bytestream + 13)
+ return -1;
+
/* read gif signature */
bytestream_get_buffer(&s->bytestream, sig, 6);
if (memcmp(sig, gif87a_sig, 6) != 0 &&
s->background_color_index = bytestream_get_byte(&s->bytestream);
bytestream_get_byte(&s->bytestream); /* ignored */
#ifdef DEBUG
- dprintf("gif: screen_w=%d screen_h=%d bpp=%d global_palette=%d\n",
+ dprintf(s->avctx, "gif: screen_w=%d screen_h=%d bpp=%d global_palette=%d\n",
s->screen_width, s->screen_height, s->bits_per_pixel,
has_global_palette);
#endif
if (has_global_palette) {
n = 1 << s->bits_per_pixel;
+ if (s->bytestream_end < s->bytestream + n * 3)
+ return -1;
bytestream_get_buffer(&s->bytestream, s->global_palette, n * 3);
}
return 0;
static int gif_parse_next_image(GifState *s)
{
- int ret, code;
-
- for (;;) {
- code = bytestream_get_byte(&s->bytestream);
+ while (s->bytestream < s->bytestream_end) {
+ int code = bytestream_get_byte(&s->bytestream);
#ifdef DEBUG
- dprintf("gif: code=%02x '%c'\n", code, code);
+ dprintf(s->avctx, "gif: code=%02x '%c'\n", code, code);
#endif
switch (code) {
case ',':
- if (gif_read_image(s) < 0)
- return -1;
- ret = 0;
- goto the_end;
- case ';':
- /* end of image */
- ret = -1;
- goto the_end;
+ return gif_read_image(s);
case '!':
if (gif_read_extension(s) < 0)
return -1;
break;
- case EOF:
+ case ';':
+ /* end of image */
default:
- /* error or errneous EOF */
- ret = -1;
- goto the_end;
+ /* error or erroneous EOF */
+ return -1;
}
}
- the_end:
- return ret;
+ return -1;
}
-static int gif_decode_init(AVCodecContext *avctx)
+static av_cold int gif_decode_init(AVCodecContext *avctx)
{
GifState *s = avctx->priv_data;
+ s->avctx = avctx;
+
avcodec_get_frame_defaults(&s->picture);
avctx->coded_frame= &s->picture;
s->picture.data[0] = NULL;
return 0;
}
-static int gif_decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
+static int gif_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
{
+ const uint8_t *buf = avpkt->data;
+ int buf_size = avpkt->size;
GifState *s = avctx->priv_data;
AVFrame *picture = data;
int ret;
s->bytestream = buf;
+ s->bytestream_end = buf + buf_size;
if (gif_read_header1(s) < 0)
return -1;
*picture = s->picture;
*data_size = sizeof(AVPicture);
- return 0;
+ return s->bytestream - buf;
}
-static int gif_decode_close(AVCodecContext *avctx)
+static av_cold int gif_decode_close(AVCodecContext *avctx)
{
GifState *s = avctx->priv_data;
NULL,
gif_decode_close,
gif_decode_frame,
+ CODEC_CAP_DR1,
+ .long_name = NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"),
};
projects / ffmpeg / blobdiff