diff options
Diffstat (limited to 'ffmpeg/libavcodec/gifdec.c')
| -rw-r--r-- | ffmpeg/libavcodec/gifdec.c | 550 |
1 files changed, 0 insertions, 550 deletions
diff --git a/ffmpeg/libavcodec/gifdec.c b/ffmpeg/libavcodec/gifdec.c deleted file mode 100644 index 78c8900..0000000 --- a/ffmpeg/libavcodec/gifdec.c +++ /dev/null @@ -1,550 +0,0 @@ -/* - * GIF decoder - * Copyright (c) 2003 Fabrice Bellard - * Copyright (c) 2006 Baptiste Coudurier - * Copyright (c) 2012 Vitaliy E Sugrobov - * - * 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 2.1 of the License, or (at your option) any later version. - * - * 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 FFmpeg; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - */ - -#include "libavutil/imgutils.h" -#include "libavutil/opt.h" -#include "avcodec.h" -#include "bytestream.h" -#include "internal.h" -#include "lzw.h" -#include "gif.h" - -/* This value is intentionally set to "transparent white" color. - * It is much better to have white background instead of black - * when gif image converted to format which not support transparency. - */ -#define GIF_TRANSPARENT_COLOR 0x00ffffff - -typedef struct GifState { - const AVClass *class; - AVFrame *frame; - int screen_width; - int screen_height; - int has_global_palette; - int bits_per_pixel; - uint32_t bg_color; - int background_color_index; - int transparent_color_index; - int color_resolution; - /* intermediate buffer for storing color indices - * obtained from lzw-encoded data stream */ - uint8_t *idx_line; - int idx_line_size; - - /* after the frame is displayed, the disposal method is used */ - int gce_prev_disposal; - int gce_disposal; - /* rectangle describing area that must be disposed */ - int gce_l, gce_t, gce_w, gce_h; - /* depending on disposal method we store either part of the image - * drawn on the canvas or background color that - * should be used upon disposal */ - uint32_t * stored_img; - int stored_img_size; - int stored_bg_color; - - GetByteContext gb; - LZWState *lzw; - - /* aux buffers */ - uint32_t global_palette[256]; - uint32_t local_palette[256]; - - AVCodecContext *avctx; - int keyframe; - int keyframe_ok; - int trans_color; /**< color value that is used instead of transparent color */ -} GifState; - -static void gif_read_palette(GifState *s, uint32_t *pal, int nb) -{ - int i; - - for (i = 0; i < nb; i++, pal++) - *pal = (0xffu << 24) | bytestream2_get_be24u(&s->gb); -} - -static void gif_fill(AVFrame *picture, uint32_t color) -{ - uint32_t *p = (uint32_t *)picture->data[0]; - uint32_t *p_end = p + (picture->linesize[0] / sizeof(uint32_t)) * picture->height; - - for (; p < p_end; p++) - *p = color; -} - -static void gif_fill_rect(AVFrame *picture, uint32_t color, int l, int t, int w, int h) -{ - const int linesize = picture->linesize[0] / sizeof(uint32_t); - const uint32_t *py = (uint32_t *)picture->data[0] + t * linesize; - const uint32_t *pr, *pb = py + h * linesize; - uint32_t *px; - - for (; py < pb; py += linesize) { - px = (uint32_t *)py + l; - pr = px + w; - - for (; px < pr; px++) - *px = color; - } -} - -static void gif_copy_img_rect(const uint32_t *src, uint32_t *dst, - int linesize, int l, int t, int w, int h) -{ - const int y_start = t * linesize; - const uint32_t *src_px, - *src_py = src + y_start, - *dst_py = dst + y_start; - const uint32_t *src_pb = src_py + h * linesize; - uint32_t *dst_px; - - for (; src_py < src_pb; src_py += linesize, dst_py += linesize) { - src_px = src_py + l; - dst_px = (uint32_t *)dst_py + l; - - memcpy(dst_px, src_px, w * sizeof(uint32_t)); - } -} - -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, pass, y1, linesize, pal_size; - uint32_t *ptr, *pal, *px, *pr, *ptr1; - int ret; - uint8_t *idx; - - /* At least 9 bytes of Image Descriptor. */ - if (bytestream2_get_bytes_left(&s->gb) < 9) - return AVERROR_INVALIDDATA; - - left = bytestream2_get_le16u(&s->gb); - top = bytestream2_get_le16u(&s->gb); - width = bytestream2_get_le16u(&s->gb); - height = bytestream2_get_le16u(&s->gb); - flags = bytestream2_get_byteu(&s->gb); - is_interleaved = flags & 0x40; - has_local_palette = flags & 0x80; - bits_per_pixel = (flags & 0x07) + 1; - - av_dlog(s->avctx, "image x=%d y=%d w=%d h=%d\n", left, top, width, height); - - if (has_local_palette) { - pal_size = 1 << bits_per_pixel; - - if (bytestream2_get_bytes_left(&s->gb) < pal_size * 3) - return AVERROR_INVALIDDATA; - - gif_read_palette(s, s->local_palette, pal_size); - pal = s->local_palette; - } else { - if (!s->has_global_palette) { - av_log(s->avctx, AV_LOG_ERROR, "picture doesn't have either global or local palette.\n"); - return AVERROR_INVALIDDATA; - } - - pal = s->global_palette; - } - - if (s->keyframe) { - if (s->transparent_color_index == -1 && s->has_global_palette) { - /* transparency wasn't set before the first frame, fill with background color */ - gif_fill(frame, s->bg_color); - } else { - /* otherwise fill with transparent color. - * this is necessary since by default picture filled with 0x80808080. */ - gif_fill(frame, s->trans_color); - } - } - - /* verify that all the image is inside the screen dimensions */ - if (left + width > s->screen_width || - top + height > s->screen_height) { - av_log(s->avctx, AV_LOG_ERROR, "image is outside the screen dimensions.\n"); - return AVERROR_INVALIDDATA; - } - if (width <= 0 || height <= 0) { - av_log(s->avctx, AV_LOG_ERROR, "Invalid image dimensions.\n"); - return AVERROR_INVALIDDATA; - } - - /* process disposal method */ - if (s->gce_prev_disposal == GCE_DISPOSAL_BACKGROUND) { - gif_fill_rect(frame, s->stored_bg_color, s->gce_l, s->gce_t, s->gce_w, s->gce_h); - } else if (s->gce_prev_disposal == GCE_DISPOSAL_RESTORE) { - gif_copy_img_rect(s->stored_img, (uint32_t *)frame->data[0], - frame->linesize[0] / sizeof(uint32_t), s->gce_l, s->gce_t, s->gce_w, s->gce_h); - } - - s->gce_prev_disposal = s->gce_disposal; - - if (s->gce_disposal != GCE_DISPOSAL_NONE) { - s->gce_l = left; s->gce_t = top; - s->gce_w = width; s->gce_h = height; - - if (s->gce_disposal == GCE_DISPOSAL_BACKGROUND) { - if (s->transparent_color_index >= 0) - s->stored_bg_color = s->trans_color; - else - s->stored_bg_color = s->bg_color; - } else if (s->gce_disposal == GCE_DISPOSAL_RESTORE) { - av_fast_malloc(&s->stored_img, &s->stored_img_size, frame->linesize[0] * frame->height); - if (!s->stored_img) - return AVERROR(ENOMEM); - - gif_copy_img_rect((uint32_t *)frame->data[0], s->stored_img, - frame->linesize[0] / sizeof(uint32_t), left, top, width, height); - } - } - - /* Expect at least 2 bytes: 1 for lzw code size and 1 for block size. */ - if (bytestream2_get_bytes_left(&s->gb) < 2) - return AVERROR_INVALIDDATA; - - /* now get the image data */ - code_size = bytestream2_get_byteu(&s->gb); - if ((ret = ff_lzw_decode_init(s->lzw, code_size, s->gb.buffer, - bytestream2_get_bytes_left(&s->gb), FF_LZW_GIF)) < 0) { - av_log(s->avctx, AV_LOG_ERROR, "LZW init failed\n"); - return ret; - } - - /* read all the image */ - linesize = frame->linesize[0] / sizeof(uint32_t); - ptr1 = (uint32_t *)frame->data[0] + top * linesize + left; - ptr = ptr1; - pass = 0; - y1 = 0; - for (y = 0; y < height; y++) { - int count = ff_lzw_decode(s->lzw, s->idx_line, width); - if (count != width) { - if (count) - av_log(s->avctx, AV_LOG_ERROR, "LZW decode failed\n"); - goto decode_tail; - } - - pr = ptr + width; - - for (px = ptr, idx = s->idx_line; px < pr; px++, idx++) { - if (*idx != s->transparent_color_index) - *px = pal[*idx]; - } - - if (is_interleaved) { - switch(pass) { - default: - case 0: - case 1: - y1 += 8; - ptr += linesize * 8; - if (y1 >= height) { - y1 = pass ? 2 : 4; - ptr = ptr1 + linesize * y1; - 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; - } - } - - decode_tail: - /* read the garbage data until end marker is found */ - ff_lzw_decode_tail(s->lzw); - - /* Graphic Control Extension's scope is single frame. - * Remove its influence. */ - s->transparent_color_index = -1; - s->gce_disposal = GCE_DISPOSAL_NONE; - - return 0; -} - -static int gif_read_extension(GifState *s) -{ - int ext_code, ext_len, gce_flags, gce_transparent_index; - - /* There must be at least 2 bytes: - * 1 for extension label and 1 for extension length. */ - if (bytestream2_get_bytes_left(&s->gb) < 2) - return AVERROR_INVALIDDATA; - - ext_code = bytestream2_get_byteu(&s->gb); - ext_len = bytestream2_get_byteu(&s->gb); - - av_dlog(s->avctx, "ext_code=0x%x len=%d\n", ext_code, ext_len); - - switch(ext_code) { - case GIF_GCE_EXT_LABEL: - if (ext_len != 4) - goto discard_ext; - - /* We need at least 5 bytes more: 4 is for extension body - * and 1 for next block size. */ - if (bytestream2_get_bytes_left(&s->gb) < 5) - return AVERROR_INVALIDDATA; - - gce_flags = bytestream2_get_byteu(&s->gb); - bytestream2_skipu(&s->gb, 2); // delay during which the frame is shown - gce_transparent_index = bytestream2_get_byteu(&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; - - av_dlog(s->avctx, "gce_flags=%x tcolor=%d disposal=%d\n", - gce_flags, - s->transparent_color_index, s->gce_disposal); - - if (s->gce_disposal > 3) { - s->gce_disposal = GCE_DISPOSAL_NONE; - av_dlog(s->avctx, "invalid value in gce_disposal (%d). Using default value of 0.\n", ext_len); - } - - ext_len = bytestream2_get_byteu(&s->gb); - break; - } - - /* NOTE: many extension blocks can come after */ - discard_ext: - while (ext_len) { - /* There must be at least ext_len bytes and 1 for next block size byte. */ - if (bytestream2_get_bytes_left(&s->gb) < ext_len + 1) - return AVERROR_INVALIDDATA; - - bytestream2_skipu(&s->gb, ext_len); - ext_len = bytestream2_get_byteu(&s->gb); - - av_dlog(s->avctx, "ext_len1=%d\n", ext_len); - } - return 0; -} - -static int gif_read_header1(GifState *s) -{ - uint8_t sig[6]; - int v, n; - int background_color_index; - - if (bytestream2_get_bytes_left(&s->gb) < 13) - return AVERROR_INVALIDDATA; - - /* read gif signature */ - bytestream2_get_bufferu(&s->gb, sig, 6); - if (memcmp(sig, gif87a_sig, 6) && - memcmp(sig, gif89a_sig, 6)) - return AVERROR_INVALIDDATA; - - /* read screen header */ - s->transparent_color_index = -1; - s->screen_width = bytestream2_get_le16u(&s->gb); - s->screen_height = bytestream2_get_le16u(&s->gb); - - v = bytestream2_get_byteu(&s->gb); - s->color_resolution = ((v & 0x70) >> 4) + 1; - s->has_global_palette = (v & 0x80); - s->bits_per_pixel = (v & 0x07) + 1; - background_color_index = bytestream2_get_byteu(&s->gb); - n = bytestream2_get_byteu(&s->gb); - if (n) { - s->avctx->sample_aspect_ratio.num = n + 15; - s->avctx->sample_aspect_ratio.den = 64; - } - - av_dlog(s->avctx, "screen_w=%d screen_h=%d bpp=%d global_palette=%d\n", - s->screen_width, s->screen_height, s->bits_per_pixel, - s->has_global_palette); - - if (s->has_global_palette) { - s->background_color_index = background_color_index; - n = 1 << s->bits_per_pixel; - if (bytestream2_get_bytes_left(&s->gb) < n * 3) - return AVERROR_INVALIDDATA; - - gif_read_palette(s, s->global_palette, n); - s->bg_color = s->global_palette[s->background_color_index]; - } else - s->background_color_index = -1; - - return 0; -} - -static int gif_parse_next_image(GifState *s, AVFrame *frame) -{ - while (bytestream2_get_bytes_left(&s->gb) > 0) { - int code = bytestream2_get_byte(&s->gb); - int ret; - - av_log(s->avctx, AV_LOG_DEBUG, "code=%02x '%c'\n", code, code); - - switch (code) { - case GIF_IMAGE_SEPARATOR: - return gif_read_image(s, frame); - case GIF_EXTENSION_INTRODUCER: - if ((ret = gif_read_extension(s)) < 0) - return ret; - break; - case GIF_TRAILER: - /* end of image */ - return AVERROR_EOF; - default: - /* erroneous block label */ - return AVERROR_INVALIDDATA; - } - } - return AVERROR_EOF; -} - -static av_cold int gif_decode_init(AVCodecContext *avctx) -{ - GifState *s = avctx->priv_data; - - s->avctx = avctx; - - avctx->pix_fmt = AV_PIX_FMT_RGB32; - s->frame = av_frame_alloc(); - if (!s->frame) - return AVERROR(ENOMEM); - ff_lzw_decode_open(&s->lzw); - return 0; -} - -static int gif_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) -{ - GifState *s = avctx->priv_data; - int ret; - - bytestream2_init(&s->gb, avpkt->data, avpkt->size); - - s->frame->pts = avpkt->pts; - s->frame->pkt_pts = avpkt->pts; - s->frame->pkt_dts = avpkt->dts; - av_frame_set_pkt_duration(s->frame, avpkt->duration); - - if (avpkt->size >= 6) { - s->keyframe = memcmp(avpkt->data, gif87a_sig, 6) == 0 || - memcmp(avpkt->data, gif89a_sig, 6) == 0; - } else { - s->keyframe = 0; - } - - if (s->keyframe) { - s->keyframe_ok = 0; - s->gce_prev_disposal = GCE_DISPOSAL_NONE; - if ((ret = gif_read_header1(s)) < 0) - return ret; - - if ((ret = ff_set_dimensions(avctx, s->screen_width, s->screen_height)) < 0) - return ret; - - av_frame_unref(s->frame); - if ((ret = ff_get_buffer(avctx, s->frame, 0)) < 0) - return ret; - - av_fast_malloc(&s->idx_line, &s->idx_line_size, s->screen_width); - if (!s->idx_line) - return AVERROR(ENOMEM); - - s->frame->pict_type = AV_PICTURE_TYPE_I; - s->frame->key_frame = 1; - s->keyframe_ok = 1; - } else { - if (!s->keyframe_ok) { - av_log(avctx, AV_LOG_ERROR, "cannot decode frame without keyframe\n"); - return AVERROR_INVALIDDATA; - } - - if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) - return ret; - - s->frame->pict_type = AV_PICTURE_TYPE_P; - s->frame->key_frame = 0; - } - - ret = gif_parse_next_image(s, s->frame); - if (ret < 0) - return ret; - - if ((ret = av_frame_ref(data, s->frame)) < 0) - return ret; - *got_frame = 1; - - return bytestream2_tell(&s->gb); -} - -static av_cold int gif_decode_close(AVCodecContext *avctx) -{ - GifState *s = avctx->priv_data; - - ff_lzw_decode_close(&s->lzw); - av_frame_free(&s->frame); - av_freep(&s->idx_line); - av_freep(&s->stored_img); - - return 0; -} - -static const AVOption options[] = { - { "trans_color", "color value (ARGB) that is used instead of transparent color", - offsetof(GifState, trans_color), AV_OPT_TYPE_INT, - {.i64 = GIF_TRANSPARENT_COLOR}, 0, 0xffffffff, - AV_OPT_FLAG_DECODING_PARAM|AV_OPT_FLAG_VIDEO_PARAM }, - { NULL }, -}; - -static const AVClass decoder_class = { - .class_name = "gif decoder", - .item_name = av_default_item_name, - .option = options, - .version = LIBAVUTIL_VERSION_INT, - .category = AV_CLASS_CATEGORY_DECODER, -}; - -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, - .priv_class = &decoder_class, -}; 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