/*
- * GIF decoder
+ * GIF demuxer
* Copyright (c) 2003 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"
//#define DEBUG
-#define MAXBITS 12
-#define SIZTABLE (1<<MAXBITS)
+#define MAXBITS 12
+#define SIZTABLE (1<<MAXBITS)
#define GCE_DISPOSAL_NONE 0
#define GCE_DISPOSAL_INPLACE 1
int background_color_index;
int transparent_color_index;
int color_resolution;
- int image_count;
uint8_t *image_buf;
+ int image_linesize;
+ uint32_t *image_palette;
+ int pix_fmt;
+
/* after the frame is displayed, the disposal method is used */
int gce_disposal;
/* delay during which the frame is shown */
int gce_delay;
-
+
/* LZW compatible decoder */
ByteIOContext *f;
int eob_reached;
int bbits;
unsigned int bbuf;
- int cursize; /* The current code size */
+ int cursize; /* The current code size */
int curmask;
int codesize;
int clear_code;
int end_code;
- int newcodes; /* First available code */
- int top_slot; /* Highest code for current size */
- int slot; /* Last read code */
+ int newcodes; /* First available code */
+ int top_slot; /* Highest code for current size */
+ int slot; /* Last read code */
int fc, oc;
uint8_t *sp;
uint8_t stack[SIZTABLE];
0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF
};
-static int gif_probe(AVProbeData * pd)
+/* Probe gif video format or gif image format. The current heuristic
+ supposes the gif87a is always a single image. For gif89a, we
+ consider it as a video only if a GCE extension is present in the
+ first kilobyte. */
+static int gif_video_probe(AVProbeData * pd)
{
- if (pd->buf_size >= 24 &&
- (memcmp(pd->buf, gif87a_sig, 6) == 0 ||
- memcmp(pd->buf, gif89a_sig, 6) == 0))
- return AVPROBE_SCORE_MAX;
- else
- return 0;
+ const uint8_t *p, *p_end;
+ int bits_per_pixel, has_global_palette, ext_code, ext_len;
+ int gce_flags, gce_disposal;
+
+ if (pd->buf_size < 24 ||
+ memcmp(pd->buf, gif89a_sig, 6) != 0)
+ return 0;
+ p_end = pd->buf + pd->buf_size;
+ p = pd->buf + 6;
+ bits_per_pixel = (p[4] & 0x07) + 1;
+ has_global_palette = (p[4] & 0x80);
+ p += 7;
+ if (has_global_palette)
+ p += (1 << bits_per_pixel) * 3;
+ for(;;) {
+ if (p >= p_end)
+ return 0;
+ if (*p != '!')
+ break;
+ p++;
+ if (p >= p_end)
+ return 0;
+ ext_code = *p++;
+ if (p >= p_end)
+ return 0;
+ ext_len = *p++;
+ if (ext_code == 0xf9) {
+ if (p >= p_end)
+ return 0;
+ /* if GCE extension found with gce_disposal != 0: it is
+ likely to be an animation */
+ gce_flags = *p++;
+ gce_disposal = (gce_flags >> 2) & 0x7;
+ if (gce_disposal != 0)
+ return AVPROBE_SCORE_MAX;
+ else
+ return 0;
+ }
+ for(;;) {
+ if (ext_len == 0)
+ break;
+ p += ext_len;
+ if (p >= p_end)
+ return 0;
+ ext_len = *p++;
+ }
+ }
+ return 0;
}
static void GLZWDecodeInit(GifState * s, int csize)
s->bbuf |= ptr[0] << s->bbits;
ptr++;
s->pbuf = ptr;
- s->bbits += 8;
+ s->bbits += 8;
}
c = s->bbuf & s->curmask;
s->bbuf >>= s->cursize;
fc = s->fc;
while (sp > s->stack) {
- *buf++ = *(--sp);
- if ((--l) == 0)
- goto the_end;
+ *buf++ = *(--sp);
+ if ((--l) == 0)
+ goto the_end;
}
for (;;) {
- c = GetCode(s);
- if (c == s->end_code) {
- s->end_code = -1;
- break;
- } else if (c == s->clear_code) {
- s->cursize = s->codesize + 1;
- s->curmask = mask[s->cursize];
- s->slot = s->newcodes;
- s->top_slot = 1 << s->cursize;
- while ((c = GetCode(s)) == s->clear_code);
- if (c == s->end_code) {
- s->end_code = -1;
- break;
- }
- /* test error */
- if (c >= s->slot)
- c = 0;
- fc = oc = c;
- *buf++ = c;
- if ((--l) == 0)
- break;
- } else {
- code = c;
- if (code >= s->slot) {
- *sp++ = fc;
- code = oc;
- }
- while (code >= s->newcodes) {
- *sp++ = s->suffix[code];
- code = s->prefix[code];
- }
- *sp++ = code;
- if (s->slot < s->top_slot) {
- s->suffix[s->slot] = fc = code;
- s->prefix[s->slot++] = oc;
- oc = c;
- }
- if (s->slot >= s->top_slot) {
- if (s->cursize < MAXBITS) {
- s->top_slot <<= 1;
- s->curmask = mask[++s->cursize];
- }
- }
- while (sp > s->stack) {
- *buf++ = *(--sp);
- if ((--l) == 0)
+ c = GetCode(s);
+ if (c == s->end_code) {
+ s->end_code = -1;
+ break;
+ } else if (c == s->clear_code) {
+ s->cursize = s->codesize + 1;
+ s->curmask = mask[s->cursize];
+ s->slot = s->newcodes;
+ s->top_slot = 1 << s->cursize;
+ while ((c = GetCode(s)) == s->clear_code);
+ if (c == s->end_code) {
+ s->end_code = -1;
+ break;
+ }
+ /* test error */
+ if (c >= s->slot)
+ c = 0;
+ fc = oc = c;
+ *buf++ = c;
+ if ((--l) == 0)
+ break;
+ } else {
+ code = c;
+ if (code >= s->slot) {
+ *sp++ = fc;
+ code = oc;
+ }
+ while (code >= s->newcodes) {
+ *sp++ = s->suffix[code];
+ code = s->prefix[code];
+ }
+ *sp++ = code;
+ if (s->slot < s->top_slot) {
+ s->suffix[s->slot] = fc = code;
+ s->prefix[s->slot++] = oc;
+ oc = c;
+ }
+ if (s->slot >= s->top_slot) {
+ if (s->cursize < MAXBITS) {
+ s->top_slot <<= 1;
+ s->curmask = mask[++s->cursize];
+ }
+ }
+ while (sp > s->stack) {
+ *buf++ = *(--sp);
+ if ((--l) == 0)
goto the_end;
- }
- }
+ }
+ }
}
the_end:
s->sp = sp;
return len - l;
}
-static int gif_read_image(AVFormatContext * s1, AVPacket * pkt)
+static int gif_read_image(GifState *s)
{
- GifState *s = s1->priv_data;
+ ByteIOContext *f = s->f;
int left, top, width, height, bits_per_pixel, code_size, flags;
- int is_interleaved, has_local_palette, y, x, linesize;
- ByteIOContext *f = &s1->pb;
- uint8_t *ptr, *line, *d, *spal, *palette, *sptr;
+ int is_interleaved, has_local_palette, y, x, pass, y1, linesize, n, i;
+ uint8_t *ptr, *line, *d, *spal, *palette, *sptr, *ptr1;
left = get_le16(f);
top = get_le16(f);
#endif
if (has_local_palette) {
- get_buffer(f, s->local_palette, 3 * (1 << bits_per_pixel));
+ get_buffer(f, s->local_palette, 3 * (1 << bits_per_pixel));
palette = s->local_palette;
} else {
palette = s->global_palette;
+ bits_per_pixel = s->bits_per_pixel;
}
-
- /* allocate local image (XXX: horrible, needs API change) */
- if (s->image_count == 0) {
- /* modify screen width/height if invalid */
- if (left + width > s->screen_width)
- s->screen_width = left + width;
- if (top + height > s->screen_height)
- s->screen_width = top + height;
- s->image_buf = av_malloc(s->screen_width * s->screen_height * 3);
- if (!s->image_buf)
- return -ENOMEM;
+
+ /* verify that all the image is inside the screen dimensions */
+ if (left + width > s->screen_width ||
+ top + height > s->screen_height)
+ return AVERROR(EINVAL);
+
+ /* build the palette */
+ if (s->pix_fmt == PIX_FMT_RGB24) {
+ line = av_malloc(width);
+ if (!line)
+ return AVERROR(ENOMEM);
} else {
- /* verify that all the image is inside the screen dimensions */
- if (left + width > s->screen_width ||
- top + height > s->screen_height)
- return -EINVAL;
+ 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]);
+ spal += 3;
+ }
+ for(; i < 256; i++)
+ s->image_palette[i] = (0xff << 24);
+ /* handle transparency */
+ if (s->transparent_color_index >= 0)
+ s->image_palette[s->transparent_color_index] = 0;
+ line = NULL;
}
- s->image_count++;
-
- line = av_malloc(width);
- if (!line)
- return -ENOMEM;
/* now get the image data */
s->f = f;
code_size = get_byte(f);
GLZWDecodeInit(s, code_size);
- /* read all the image and transcode it to RGB24 (horrible) */
- linesize = s->screen_width * 3;
- ptr = s->image_buf + top * linesize + (left * 3);
+ /* read all the image */
+ linesize = s->image_linesize;
+ ptr1 = s->image_buf + top * linesize + (left * 3);
+ ptr = ptr1;
+ pass = 0;
+ y1 = 0;
for (y = 0; y < height; y++) {
- GLZWDecode(s, line, width);
- d = ptr;
- sptr = line;
- for(x = 0; x < width; x++) {
- spal = palette + sptr[0] * 3;
- d[0] = spal[0];
- d[1] = spal[1];
- d[2] = spal[2];
- d += 3;
- sptr++;
+ if (s->pix_fmt == PIX_FMT_RGB24) {
+ /* transcode to RGB24 */
+ GLZWDecode(s, line, width);
+ d = ptr;
+ sptr = line;
+ for(x = 0; x < width; x++) {
+ spal = palette + sptr[0] * 3;
+ d[0] = spal[0];
+ d[1] = spal[1];
+ d[2] = spal[2];
+ d += 3;
+ sptr++;
+ }
+ } else {
+ GLZWDecode(s, ptr, width);
+ }
+ if (is_interleaved) {
+ switch(pass) {
+ default:
+ case 0:
+ case 1:
+ y1 += 8;
+ ptr += linesize * 8;
+ if (y1 >= height) {
+ y1 = 4;
+ if (pass == 0)
+ ptr = ptr1 + linesize * 4;
+ else
+ ptr = ptr1 + linesize * 2;
+ pass++;
+ }
+ break;
+ case 2:
+ y1 += 4;
+ ptr += linesize * 4;
+ if (y1 >= height) {
+ y1 = 1;
+ ptr = ptr1 + linesize;
+ pass++;
+ }
+ break;
+ case 3:
+ y1 += 2;
+ ptr += linesize * 2;
+ break;
+ }
+ } else {
+ ptr += linesize;
}
- ptr += linesize;
}
av_free(line);
-
+
/* read the garbage data until end marker is found */
while (!s->eob_reached)
GetCode(s);
-
- /* output image */
- /* XXX: avoid copying */
- if (av_new_packet(pkt, s->screen_width * s->screen_height * 3)) {
- av_free(line);
- return -EIO;
- }
- pkt->stream_index = 0;
- memcpy(pkt->data, s->image_buf, s->screen_width * s->screen_height * 3);
return 0;
}
-static int gif_read_extension(AVFormatContext * s1)
+static int gif_read_extension(GifState *s)
{
- GifState *s = s1->priv_data;
- ByteIOContext *f = &s1->pb;
+ ByteIOContext *f = s->f;
int ext_code, ext_len, i, gce_flags, gce_transparent_index;
/* extension */
s->transparent_color_index = -1;
s->gce_disposal = (gce_flags >> 2) & 0x7;
#ifdef DEBUG
- printf("gif: gce_flags=%x delay=%d tcolor=%d disposal=%d\n",
- gce_flags, s->gce_delay,
+ printf("gif: gce_flags=%x delay=%d tcolor=%d disposal=%d\n",
+ gce_flags, s->gce_delay,
s->transparent_color_index, s->gce_disposal);
#endif
ext_len = get_byte(f);
break;
}
-
+
/* NOTE: many extension blocks can come after */
discard_ext:
while (ext_len != 0) {
return 0;
}
-static int gif_read_header(AVFormatContext * s1,
- AVFormatParameters * ap)
+static int gif_read_header1(GifState *s)
{
- GifState *s = s1->priv_data;
- ByteIOContext *f = &s1->pb;
- AVStream *st;
+ ByteIOContext *f = s->f;
uint8_t sig[6];
int ret, v, n;
int has_global_palette;
/* read gif signature */
ret = get_buffer(f, sig, 6);
if (ret != 6)
- return -1;
+ return -1;
if (memcmp(sig, gif87a_sig, 6) != 0 &&
- memcmp(sig, gif89a_sig, 6) != 0)
- return -1;
+ memcmp(sig, gif89a_sig, 6) != 0)
+ return -1;
/* read screen header */
s->transparent_color_index = -1;
s->screen_width = get_le16(f);
s->screen_height = get_le16(f);
+ if( (unsigned)s->screen_width > 32767
+ || (unsigned)s->screen_height > 32767){
+ av_log(NULL, AV_LOG_ERROR, "picture size too large\n");
+ return -1;
+ }
+
v = get_byte(f);
s->color_resolution = ((v & 0x70) >> 4) + 1;
has_global_palette = (v & 0x80);
s->bits_per_pixel = (v & 0x07) + 1;
s->background_color_index = get_byte(f);
- get_byte(f); /* ignored */
+ get_byte(f); /* ignored */
#ifdef DEBUG
printf("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);
+ s->screen_width, s->screen_height, s->bits_per_pixel,
+ has_global_palette);
#endif
if (has_global_palette) {
- n = 1 << s->bits_per_pixel;
- get_buffer(f, s->global_palette, n * 3);
+ n = 1 << s->bits_per_pixel;
+ get_buffer(f, s->global_palette, n * 3);
}
- /* now we are ready: build format streams */
- st = av_new_stream(s1, 0);
- if (!st)
- return -1;
-
- st->codec.codec_type = CODEC_TYPE_VIDEO;
- st->codec.codec_id = CODEC_ID_RAWVIDEO;
- st->codec.frame_rate = 5 * FRAME_RATE_BASE;
- /* XXX: check if screen size is always valid */
- st->codec.width = s->screen_width;
- st->codec.height = s->screen_height;
- st->codec.pix_fmt = PIX_FMT_RGB24;
return 0;
}
-static int gif_read_packet(AVFormatContext * s1,
- AVPacket * pkt)
+static int gif_parse_next_image(GifState *s)
{
- ByteIOContext *f = &s1->pb;
+ ByteIOContext *f = s->f;
int ret, code;
for (;;) {
- code = url_fgetc(f);
+ code = url_fgetc(f);
#ifdef DEBUG
- printf("gif: code=%02x '%c'\n", code, code);
+ printf("gif: code=%02x '%c'\n", code, code);
#endif
- switch (code) {
- case ',':
- if (gif_read_image(s1, pkt) < 0)
- return -EIO;
- ret = 0;
- goto the_end;
- case ';':
- /* end of image */
- ret = -EIO;
- goto the_end;
- case '!':
- if (gif_read_extension(s1) < 0)
- return -EIO;
- break;
- case EOF:
- default:
- /* error or errneous EOF */
- ret = -EIO;
- goto the_end;
- }
+ switch (code) {
+ case ',':
+ if (gif_read_image(s) < 0)
+ return AVERROR(EIO);
+ ret = 0;
+ goto the_end;
+ case ';':
+ /* end of image */
+ ret = AVERROR(EIO);
+ goto the_end;
+ case '!':
+ if (gif_read_extension(s) < 0)
+ return AVERROR(EIO);
+ break;
+ case EOF:
+ default:
+ /* error or errneous EOF */
+ ret = AVERROR(EIO);
+ goto the_end;
+ }
}
the_end:
return ret;
}
+static int gif_read_header(AVFormatContext * s1,
+ AVFormatParameters * ap)
+{
+ GifState *s = s1->priv_data;
+ ByteIOContext *f = &s1->pb;
+ AVStream *st;
+
+ s->f = f;
+ if (gif_read_header1(s) < 0)
+ return -1;
+
+ /* allocate image buffer */
+ s->image_linesize = s->screen_width * 3;
+ s->image_buf = av_malloc(s->screen_height * s->image_linesize);
+ if (!s->image_buf)
+ return AVERROR(ENOMEM);
+ s->pix_fmt = PIX_FMT_RGB24;
+ /* now we are ready: build format streams */
+ st = av_new_stream(s1, 0);
+ if (!st)
+ return -1;
+
+ st->codec->codec_type = CODEC_TYPE_VIDEO;
+ st->codec->codec_id = CODEC_ID_RAWVIDEO;
+ st->codec->time_base.den = 5;
+ st->codec->time_base.num = 1;
+ /* XXX: check if screen size is always valid */
+ st->codec->width = s->screen_width;
+ st->codec->height = s->screen_height;
+ st->codec->pix_fmt = PIX_FMT_RGB24;
+ return 0;
+}
+
+static int gif_read_packet(AVFormatContext * s1,
+ AVPacket * pkt)
+{
+ GifState *s = s1->priv_data;
+ int ret;
+
+ ret = gif_parse_next_image(s);
+ if (ret < 0)
+ return ret;
+
+ /* XXX: avoid copying */
+ if (av_new_packet(pkt, s->screen_width * s->screen_height * 3)) {
+ return AVERROR(EIO);
+ }
+ pkt->stream_index = 0;
+ memcpy(pkt->data, s->image_buf, s->screen_width * s->screen_height * 3);
+ return 0;
+}
+
static int gif_read_close(AVFormatContext *s1)
{
GifState *s = s1->priv_data;
return 0;
}
-AVInputFormat gif_iformat =
+AVInputFormat gif_demuxer =
{
"gif",
"gif format",
sizeof(GifState),
- gif_probe,
+ gif_video_probe,
gif_read_header,
gif_read_packet,
gif_read_close,
projects / ffmpeg / blobdiff