diff options
Diffstat (limited to 'libavcodec/gif.c')
| -rw-r--r-- | libavcodec/gif.c | 28 |
1 files changed, 20 insertions, 8 deletions
diff --git a/libavcodec/gif.c b/libavcodec/gif.c index 7f602989e2..ec4be2749b 100644 --- a/libavcodec/gif.c +++ b/libavcodec/gif.c @@ -4,20 +4,20 @@ * Copyright (c) 2002 Francois Revol * Copyright (c) 2006 Baptiste Coudurier * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * 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. * - * Libav 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 Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -63,7 +63,7 @@ static int gif_image_write_header(AVCodecContext *avctx, uint8_t **bytestream, uint32_t *palette) { int i; - unsigned int v; + unsigned int v, smallest_alpha = 0xFF, alpha_component = 0; bytestream_put_buffer(bytestream, "GIF", 3); bytestream_put_buffer(bytestream, "89a", 3); @@ -78,6 +78,20 @@ static int gif_image_write_header(AVCodecContext *avctx, for(i=0;i<256;i++) { v = palette[i]; bytestream_put_be24(bytestream, v); + if (v >> 24 < smallest_alpha) { + smallest_alpha = v >> 24; + alpha_component = i; + } + } + + if (smallest_alpha < 128) { + bytestream_put_byte(bytestream, 0x21); /* Extension Introducer */ + bytestream_put_byte(bytestream, 0xf9); /* Graphic Control Label */ + bytestream_put_byte(bytestream, 0x04); /* block length */ + bytestream_put_byte(bytestream, 0x01); /* Transparent Color Flag */ + bytestream_put_le16(bytestream, 0x00); /* no delay */ + bytestream_put_byte(bytestream, alpha_component); + bytestream_put_byte(bytestream, 0x00); } return 0; @@ -150,10 +164,8 @@ static int gif_encode_frame(AVCodecContext *avctx, AVPacket *pkt, uint8_t *outbuf_ptr, *end; int ret; - if ((ret = ff_alloc_packet(pkt, avctx->width*avctx->height*7/5 + FF_MIN_BUFFER_SIZE)) < 0) { - av_log(avctx, AV_LOG_ERROR, "Error getting output packet.\n"); + if ((ret = ff_alloc_packet2(avctx, pkt, avctx->width*avctx->height*7/5 + FF_MIN_BUFFER_SIZE)) < 0) return ret; - } outbuf_ptr = pkt->data; end = pkt->data + pkt->size; |