| 0,0 → 1,222 |
|---|
| /* |
| * Animated GIF muxer |
| * Copyright (c) 2000 Fabrice Bellard |
| * |
| * first version by Francois Revol <revol@free.fr> |
| * |
| * 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 "avformat.h" |
| #include "internal.h" |
| #include "libavutil/avassert.h" |
| #include "libavutil/imgutils.h" |
| #include "libavutil/log.h" |
| #include "libavutil/opt.h" |
| |
| static int gif_image_write_header(AVIOContext *pb, int width, int height, |
| int loop_count, uint32_t *palette) |
| { |
| int i; |
| |
| avio_write(pb, "GIF", 3); |
| avio_write(pb, "89a", 3); |
| avio_wl16(pb, width); |
| avio_wl16(pb, height); |
| |
| if (palette) { |
| avio_w8(pb, 0xf7); /* flags: global clut, 256 entries */ |
| avio_w8(pb, 0x1f); /* background color index */ |
| avio_w8(pb, 0); /* aspect ratio */ |
| for (i = 0; i < 256; i++) { |
| const uint32_t v = palette[i] & 0xffffff; |
| avio_wb24(pb, v); |
| } |
| } else { |
| avio_w8(pb, 0); /* flags */ |
| avio_w8(pb, 0); /* background color index */ |
| avio_w8(pb, 0); /* aspect ratio */ |
| } |
| |
| |
| if (loop_count >= 0 ) { |
| /* "NETSCAPE EXTENSION" for looped animation GIF */ |
| avio_w8(pb, 0x21); /* GIF Extension code */ |
| avio_w8(pb, 0xff); /* Application Extension Label */ |
| avio_w8(pb, 0x0b); /* Length of Application Block */ |
| avio_write(pb, "NETSCAPE2.0", sizeof("NETSCAPE2.0") - 1); |
| avio_w8(pb, 0x03); /* Length of Data Sub-Block */ |
| avio_w8(pb, 0x01); |
| avio_wl16(pb, (uint16_t)loop_count); |
| avio_w8(pb, 0x00); /* Data Sub-block Terminator */ |
| } |
| |
| return 0; |
| } |
| |
| typedef struct { |
| AVClass *class; |
| int loop; |
| int last_delay; |
| AVPacket *prev_pkt; |
| int duration; |
| } GIFContext; |
| |
| static int gif_write_header(AVFormatContext *s) |
| { |
| GIFContext *gif = s->priv_data; |
| AVIOContext *pb = s->pb; |
| AVCodecContext *video_enc; |
| int width, height; |
| uint32_t palette[AVPALETTE_COUNT]; |
| |
| if (s->nb_streams != 1 || |
| s->streams[0]->codec->codec_type != AVMEDIA_TYPE_VIDEO || |
| s->streams[0]->codec->codec_id != AV_CODEC_ID_GIF) { |
| av_log(s, AV_LOG_ERROR, |
| "GIF muxer supports only a single video GIF stream.\n"); |
| return AVERROR(EINVAL); |
| } |
| |
| video_enc = s->streams[0]->codec; |
| width = video_enc->width; |
| height = video_enc->height; |
| |
| avpriv_set_pts_info(s->streams[0], 64, 1, 100); |
| if (avpriv_set_systematic_pal2(palette, video_enc->pix_fmt) < 0) { |
| av_assert0(video_enc->pix_fmt == AV_PIX_FMT_PAL8); |
| gif_image_write_header(pb, width, height, gif->loop, NULL); |
| } else { |
| gif_image_write_header(pb, width, height, gif->loop, palette); |
| } |
| |
| avio_flush(s->pb); |
| return 0; |
| } |
| |
| static int flush_packet(AVFormatContext *s, AVPacket *new) |
| { |
| GIFContext *gif = s->priv_data; |
| int size; |
| AVIOContext *pb = s->pb; |
| uint8_t flags = 0x4, transparent_color_index = 0x1f; |
| const uint32_t *palette; |
| AVPacket *pkt = gif->prev_pkt; |
| |
| if (!pkt) |
| return 0; |
| |
| /* Mark one colour as transparent if the input palette contains at least |
| * one colour that is more than 50% transparent. */ |
| palette = (uint32_t*)av_packet_get_side_data(pkt, AV_PKT_DATA_PALETTE, &size); |
| if (palette && size != AVPALETTE_SIZE) { |
| av_log(s, AV_LOG_ERROR, "Invalid palette extradata\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| if (palette) { |
| unsigned i, smallest_alpha = 0xff; |
| |
| for (i = 0; i < AVPALETTE_COUNT; i++) { |
| const uint32_t v = palette[i]; |
| if (v >> 24 < smallest_alpha) { |
| smallest_alpha = v >> 24; |
| transparent_color_index = i; |
| } |
| } |
| if (smallest_alpha < 128) |
| flags |= 0x1; /* Transparent Color Flag */ |
| } |
| |
| if (new && new->pts != AV_NOPTS_VALUE) |
| gif->duration = av_clip_uint16(new->pts - gif->prev_pkt->pts); |
| else if (!new && gif->last_delay >= 0) |
| gif->duration = gif->last_delay; |
| |
| /* graphic control extension block */ |
| avio_w8(pb, 0x21); |
| avio_w8(pb, 0xf9); |
| avio_w8(pb, 0x04); /* block size */ |
| avio_w8(pb, flags); |
| avio_wl16(pb, gif->duration); |
| avio_w8(pb, transparent_color_index); |
| avio_w8(pb, 0x00); |
| |
| avio_write(pb, pkt->data, pkt->size); |
| |
| av_free_packet(gif->prev_pkt); |
| if (new) |
| av_copy_packet(gif->prev_pkt, new); |
| |
| return 0; |
| } |
| |
| static int gif_write_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| GIFContext *gif = s->priv_data; |
| |
| if (!gif->prev_pkt) { |
| gif->prev_pkt = av_malloc(sizeof(*gif->prev_pkt)); |
| if (!gif->prev_pkt) |
| return AVERROR(ENOMEM); |
| return av_copy_packet(gif->prev_pkt, pkt); |
| } |
| return flush_packet(s, pkt); |
| } |
| |
| static int gif_write_trailer(AVFormatContext *s) |
| { |
| GIFContext *gif = s->priv_data; |
| AVIOContext *pb = s->pb; |
| |
| flush_packet(s, NULL); |
| av_freep(&gif->prev_pkt); |
| avio_w8(pb, 0x3b); |
| |
| return 0; |
| } |
| |
| #define OFFSET(x) offsetof(GIFContext, x) |
| #define ENC AV_OPT_FLAG_ENCODING_PARAM |
| static const AVOption options[] = { |
| { "loop", "Number of times to loop the output: -1 - no loop, 0 - infinite loop", OFFSET(loop), |
| AV_OPT_TYPE_INT, { .i64 = 0 }, -1, 65535, ENC }, |
| { "final_delay", "Force delay (in ms) after the last frame", OFFSET(last_delay), |
| AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 65535, ENC }, |
| { NULL }, |
| }; |
| |
| static const AVClass gif_muxer_class = { |
| .class_name = "GIF muxer", |
| .item_name = av_default_item_name, |
| .version = LIBAVUTIL_VERSION_INT, |
| .option = options, |
| }; |
| |
| AVOutputFormat ff_gif_muxer = { |
| .name = "gif", |
| .long_name = NULL_IF_CONFIG_SMALL("GIF Animation"), |
| .mime_type = "image/gif", |
| .extensions = "gif", |
| .priv_data_size = sizeof(GIFContext), |
| .audio_codec = AV_CODEC_ID_NONE, |
| .video_codec = AV_CODEC_ID_GIF, |
| .write_header = gif_write_header, |
| .write_packet = gif_write_packet, |
| .write_trailer = gif_write_trailer, |
| .priv_class = &gif_muxer_class, |
| .flags = AVFMT_VARIABLE_FPS, |
| }; |