X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fgifdec.c;h=d91f159dc1640d00f0d508d11e8d129aae9c6ce7;hb=7f596368a404363d72b1be6d16c51420a71bc523;hp=6ae0bdd25f77eb5691e41b39b9c8bd16662d955e;hpb=8e57cae794466cf40c6a10df56d99eb16a90b89e;p=ffmpeg diff --git a/libavcodec/gifdec.c b/libavcodec/gifdec.c index 6ae0bdd25f7..d91f159dc16 100644 --- a/libavcodec/gifdec.c +++ b/libavcodec/gifdec.c @@ -1,32 +1,30 @@ /* * 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. + * This file is part of Libav. * - * FFmpeg is free software; you can redistribute it and/or + * Libav 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 2.1 of the License, or (at your option) any later version. * - * FFmpeg is distributed in the hope that it will be useful, + * Libav 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 FFmpeg; if not, write to the Free Software + * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ -//#define DEBUG - +#include "libavutil/imgutils.h" #include "avcodec.h" #include "bytestream.h" - -#define MAXBITS 12 -#define SIZTABLE (1<eob_reached = 0; - s->pbuf = s->buf; - s->ebuf = s->buf; - s->bbuf = 0; - s->bbits = 0; - - /* decoder */ - s->codesize = csize; - s->cursize = s->codesize + 1; - s->curmask = mask[s->cursize]; - s->top_slot = 1 << s->cursize; - s->clear_code = 1 << s->codesize; - s->end_code = s->clear_code + 1; - s->slot = s->newcodes = s->clear_code + 2; - s->oc = s->fc = 0; - s->sp = s->stack; -} - -/* XXX: optimize */ -static inline int GetCode(GifState * s) -{ - int c, sizbuf; - uint8_t *ptr; - - while (s->bbits < s->cursize) { - ptr = s->pbuf; - if (ptr >= s->ebuf) { - if (!s->eob_reached) { - sizbuf = bytestream_get_byte(&s->bytestream); - s->ebuf = s->buf + sizbuf; - s->pbuf = s->buf; - if (sizbuf > 0) { - bytestream_get_buffer(&s->bytestream, s->buf, sizbuf); - } else { - s->eob_reached = 1; - } - } - ptr = s->pbuf; - } - s->bbuf |= ptr[0] << s->bbits; - ptr++; - s->pbuf = ptr; - s->bbits += 8; - } - c = s->bbuf & s->curmask; - s->bbuf >>= s->cursize; - s->bbits -= s->cursize; - return c; -} - -/* NOTE: the algorithm here is inspired from the LZW GIF decoder - written by Steven A. Bennett in 1987. */ -/* return the number of byte decoded */ -static int GLZWDecode(GifState * s, uint8_t * buf, int len) -{ - int l, c, code, oc, fc; - uint8_t *sp; - - if (s->end_code < 0) - return 0; - - l = len; - sp = s->sp; - oc = s->oc; - fc = s->fc; - - while (sp > s->stack) { - *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) - goto the_end; - } - } - } - the_end: - s->sp = sp; - s->oc = oc; - s->fc = fc; - return len - l; -} - -static int gif_read_image(GifState *s) +static int gif_read_image(GifState *s, AVFrame *frame) { int left, top, width, height, bits_per_pixel, code_size, flags; - int is_interleaved, has_local_palette, y, x, pass, y1, linesize, n, i; - uint8_t *ptr, *line, *d, *spal, *palette, *sptr, *ptr1; - - left = bytestream_get_le16(&s->bytestream); - top = bytestream_get_le16(&s->bytestream); - width = bytestream_get_le16(&s->bytestream); - height = bytestream_get_le16(&s->bytestream); - flags = bytestream_get_byte(&s->bytestream); + int is_interleaved, has_local_palette, y, pass, y1, linesize, n, i; + uint8_t *ptr, *spal, *palette, *ptr1; + + left = bytestream2_get_le16(&s->gb); + top = bytestream2_get_le16(&s->gb); + width = bytestream2_get_le16(&s->gb); + height = bytestream2_get_le16(&s->gb); + flags = bytestream2_get_byte(&s->gb); is_interleaved = flags & 0x40; has_local_palette = flags & 0x80; bits_per_pixel = (flags & 0x07) + 1; -#ifdef DEBUG - printf("gif: image x=%d y=%d w=%d h=%d\n", left, top, width, height); -#endif + + ff_dlog(s->avctx, "gif: image x=%d y=%d w=%d h=%d\n", left, top, width, height); if (has_local_palette) { - bytestream_get_buffer(&s->bytestream, s->local_palette, 3 * (1 << bits_per_pixel)); + bytestream2_get_buffer(&s->gb, s->local_palette, 3 * (1 << bits_per_pixel)); palette = s->local_palette; } else { palette = s->global_palette; @@ -249,36 +86,38 @@ static int gif_read_image(GifState *s) /* verify that all the image is inside the screen dimensions */ if (left + width > s->screen_width || - top + height > s->screen_height) - return -EINVAL; + top + height > s->screen_height || + !width || !height) { + av_log(s->avctx, AV_LOG_ERROR, "Invalid image dimensions.\n"); + return AVERROR_INVALIDDATA; + } /* 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]); - 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; + n = (1 << bits_per_pixel); + spal = palette; + for(i = 0; i < n; i++) { + s->image_palette[i] = (0xffu << 24) | AV_RB24(spal); + spal += 3; + } + for(; i < 256; i++) + s->image_palette[i] = (0xffu << 24); + /* handle transparency */ + if (s->transparent_color_index >= 0) + s->image_palette[s->transparent_color_index] = 0; /* now get the image data */ - code_size = bytestream_get_byte(&s->bytestream); - GLZWDecodeInit(s, code_size); + code_size = bytestream2_get_byte(&s->gb); + ff_lzw_decode_init(s->lzw, code_size, s->gb.buffer, + bytestream2_get_bytes_left(&s->gb), FF_LZW_GIF); /* read all the image */ - linesize = s->image_linesize; - ptr1 = s->image_buf + top * linesize + (left * 3); + linesize = frame->linesize[0]; + ptr1 = frame->data[0] + top * linesize + left; ptr = ptr1; pass = 0; y1 = 0; for (y = 0; y < height; y++) { - GLZWDecode(s, ptr, width); + ff_lzw_decode(s->lzw, ptr, width); if (is_interleaved) { switch(pass) { default: @@ -286,38 +125,29 @@ static int gif_read_image(GifState *s) 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; } + while (y1 >= height) { + y1 = 4 >> pass; + ptr = ptr1 + linesize * y1; + pass++; + } } else { ptr += linesize; } } - av_free(line); - /* read the garbage data until end marker is found */ - while (!s->eob_reached) - GetCode(s); + ff_lzw_decode_tail(s->lzw); + + bytestream2_skip(&s->gb, ff_lzw_size_read(s->lzw)); return 0; } @@ -326,30 +156,30 @@ static int gif_read_extension(GifState *s) int ext_code, ext_len, i, gce_flags, gce_transparent_index; /* extension */ - ext_code = bytestream_get_byte(&s->bytestream); - ext_len = bytestream_get_byte(&s->bytestream); -#ifdef DEBUG - printf("gif: ext_code=0x%x len=%d\n", ext_code, ext_len); -#endif + ext_code = bytestream2_get_byte(&s->gb); + ext_len = bytestream2_get_byte(&s->gb); + + ff_dlog(s->avctx, "gif: ext_code=0x%x len=%d\n", ext_code, ext_len); + switch(ext_code) { case 0xf9: if (ext_len != 4) goto discard_ext; s->transparent_color_index = -1; - gce_flags = bytestream_get_byte(&s->bytestream); - s->gce_delay = bytestream_get_le16(&s->bytestream); - gce_transparent_index = bytestream_get_byte(&s->bytestream); + gce_flags = bytestream2_get_byte(&s->gb); + s->gce_delay = bytestream2_get_le16(&s->gb); + gce_transparent_index = bytestream2_get_byte(&s->gb); if (gce_flags & 0x01) s->transparent_color_index = gce_transparent_index; else 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", + + ff_dlog(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 - ext_len = bytestream_get_byte(&s->bytestream); + + ext_len = bytestream2_get_byte(&s->gb); break; } @@ -357,11 +187,10 @@ static int gif_read_extension(GifState *s) discard_ext: while (ext_len != 0) { for (i = 0; i < ext_len; i++) - bytestream_get_byte(&s->bytestream); - ext_len = bytestream_get_byte(&s->bytestream); -#ifdef DEBUG - printf("gif: ext_len1=%d\n", ext_len); -#endif + bytestream2_get_byte(&s->gb); + ext_len = bytestream2_get_byte(&s->gb); + + ff_dlog(s->avctx, "gif: ext_len1=%d\n", ext_len); } return 0; } @@ -369,127 +198,130 @@ static int gif_read_extension(GifState *s) static int gif_read_header1(GifState *s) { uint8_t sig[6]; - int ret, v, n; + int v, n; int has_global_palette; + if (bytestream2_get_bytes_left(&s->gb) < 13) + return AVERROR_INVALIDDATA; + /* read gif signature */ - bytestream_get_buffer(&s->bytestream, sig, 6); + bytestream2_get_buffer(&s->gb, sig, 6); if (memcmp(sig, gif87a_sig, 6) != 0 && memcmp(sig, gif89a_sig, 6) != 0) - return -1; + return AVERROR_INVALIDDATA; /* read screen header */ s->transparent_color_index = -1; - s->screen_width = bytestream_get_le16(&s->bytestream); - s->screen_height = bytestream_get_le16(&s->bytestream); + s->screen_width = bytestream2_get_le16(&s->gb); + s->screen_height = bytestream2_get_le16(&s->gb); if( (unsigned)s->screen_width > 32767 || (unsigned)s->screen_height > 32767){ av_log(NULL, AV_LOG_ERROR, "picture size too large\n"); - return -1; + return AVERROR_INVALIDDATA; } - v = bytestream_get_byte(&s->bytestream); + v = bytestream2_get_byte(&s->gb); s->color_resolution = ((v & 0x70) >> 4) + 1; has_global_palette = (v & 0x80); s->bits_per_pixel = (v & 0x07) + 1; - s->background_color_index = bytestream_get_byte(&s->bytestream); - bytestream_get_byte(&s->bytestream); /* ignored */ -#ifdef DEBUG - printf("gif: screen_w=%d screen_h=%d bpp=%d global_palette=%d\n", + s->background_color_index = bytestream2_get_byte(&s->gb); + bytestream2_get_byte(&s->gb); /* ignored */ + + ff_dlog(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; - bytestream_get_buffer(&s->bytestream, s->global_palette, n * 3); + if (bytestream2_get_bytes_left(&s->gb) < n * 3) + return AVERROR_INVALIDDATA; + bytestream2_get_buffer(&s->gb, s->global_palette, n * 3); } return 0; } -static int gif_parse_next_image(GifState *s) +static int gif_parse_next_image(GifState *s, AVFrame *frame) { - int ret, code; + while (bytestream2_get_bytes_left(&s->gb) > 0) { + int code = bytestream2_get_byte(&s->gb); + int ret; + + ff_dlog(s->avctx, "gif: code=%02x '%c'\n", code, code); - for (;;) { - code = bytestream_get_byte(&s->bytestream); -#ifdef DEBUG - printf("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, frame); case '!': - if (gif_read_extension(s) < 0) - return -1; + if ((ret = gif_read_extension(s)) < 0) + return ret; break; - case EOF: + case ';': + /* end of image */ default: - /* error or errneous EOF */ - ret = -1; - goto the_end; + /* error or erroneous EOF */ + return AVERROR_INVALIDDATA; } } - the_end: - return ret; + return AVERROR_INVALIDDATA; } -static int gif_decode_init(AVCodecContext *avctx) +static av_cold int gif_decode_init(AVCodecContext *avctx) { GifState *s = avctx->priv_data; + s->avctx = avctx; + + ff_lzw_decode_open(&s->lzw); 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 *got_frame, + 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; - if (gif_read_header1(s) < 0) - return -1; + bytestream2_init(&s->gb, buf, buf_size); + if ((ret = gif_read_header1(s)) < 0) + return ret; - /* 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 -ENOMEM; - s->pix_fmt = PIX_FMT_PAL8; - /* now we are ready: build format streams */ + avctx->pix_fmt = AV_PIX_FMT_PAL8; - /* XXX: check if screen size is always valid */ - avctx->width = s->screen_width; - avctx->height = s->screen_height; - avctx->pix_fmt = PIX_FMT_PAL8; + if ((ret = ff_set_dimensions(avctx, s->screen_width, s->screen_height)) < 0) + return ret; - ret = gif_parse_next_image(s); + if ((ret = ff_get_buffer(avctx, picture, 0)) < 0) { + av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); + return ret; + } + s->image_palette = (uint32_t *)picture->data[1]; + ret = gif_parse_next_image(s, picture); if (ret < 0) return ret; - picture->data[0] = s->image_buf; - picture->linesize[0] = s->image_linesize; - picture->data[1] = s->image_palette; - picture->linesize[1] = 4; + *got_frame = 1; + return bytestream2_tell(&s->gb); +} + +static av_cold int gif_decode_close(AVCodecContext *avctx) +{ + GifState *s = avctx->priv_data; - *data_size = sizeof(AVPicture); + ff_lzw_decode_close(&s->lzw); return 0; } -AVCodec gif_decoder = { - "gif", - CODEC_TYPE_VIDEO, - CODEC_ID_GIF, - sizeof(GifState), - gif_decode_init, - NULL, - NULL, - gif_decode_frame, +AVCodec ff_gif_decoder = { + .name = "gif", + .long_name = NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"), + .type = AVMEDIA_TYPE_VIDEO, + .id = AV_CODEC_ID_GIF, + .priv_data_size = sizeof(GifState), + .init = gif_decode_init, + .close = gif_decode_close, + .decode = gif_decode_frame, + .capabilities = CODEC_CAP_DR1, };