| /* |
| * Copyright (c) 2000 Fabrice Bellard |
| * Copyright (c) 2002 Francois Revol |
| * Copyright (c) 2006 Baptiste Coudurier |
| * |
| * 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 |
| */ |
| |
| /** |
| * @file |
| * GIF encoder |
| * @see http://www.w3.org/Graphics/GIF/spec-gif89a.txt |
| */ |
| |
| #define BITSTREAM_WRITER_LE |
| #include "libavutil/opt.h" |
| #include "libavutil/imgutils.h" |
| #include "avcodec.h" |
| #include "bytestream.h" |
| #include "internal.h" |
| #include "lzw.h" |
| #include "gif.h" |
| |
| #include "put_bits.h" |
| |
| typedef struct GIFContext { |
| const AVClass *class; |
| LZWState *lzw; |
| uint8_t *buf; |
| int buf_size; |
| AVFrame *last_frame; |
| int flags; |
| uint32_t palette[AVPALETTE_COUNT]; ///< local reference palette for !pal8 |
| int palette_loaded; |
| int transparent_index; |
| uint8_t *pal_exdata; |
| uint8_t *tmpl; ///< temporary line buffer |
| } GIFContext; |
| |
| enum { |
| GF_OFFSETTING = 1<<0, |
| GF_TRANSDIFF = 1<<1, |
| }; |
| |
| static int pick_palette_entry(const uint8_t *buf, int linesize, int w, int h) |
| { |
| int histogram[AVPALETTE_COUNT] = {0}; |
| int x, y, i; |
| |
| for (y = 0; y < h; y++) { |
| for (x = 0; x < w; x++) |
| histogram[buf[x]]++; |
| buf += linesize; |
| } |
| for (i = 0; i < FF_ARRAY_ELEMS(histogram); i++) |
| if (!histogram[i]) |
| return i; |
| return -1; |
| } |
| |
| static int gif_image_write_image(AVCodecContext *avctx, |
| uint8_t **bytestream, uint8_t *end, |
| const uint32_t *palette, |
| const uint8_t *buf, const int linesize, |
| AVPacket *pkt) |
| { |
| GIFContext *s = avctx->priv_data; |
| int len = 0, height = avctx->height, width = avctx->width, x, y; |
| int x_start = 0, y_start = 0, trans = s->transparent_index; |
| int honor_transparency = (s->flags & GF_TRANSDIFF) && s->last_frame && !palette; |
| const uint8_t *ptr; |
| |
| /* Crop image */ |
| if ((s->flags & GF_OFFSETTING) && s->last_frame && !palette) { |
| const uint8_t *ref = s->last_frame->data[0]; |
| const int ref_linesize = s->last_frame->linesize[0]; |
| int x_end = avctx->width - 1, |
| y_end = avctx->height - 1; |
| |
| /* skip common lines */ |
| while (y_start < y_end) { |
| if (memcmp(ref + y_start*ref_linesize, buf + y_start*linesize, width)) |
| break; |
| y_start++; |
| } |
| while (y_end > y_start) { |
| if (memcmp(ref + y_end*ref_linesize, buf + y_end*linesize, width)) |
| break; |
| y_end--; |
| } |
| height = y_end + 1 - y_start; |
| |
| /* skip common columns */ |
| while (x_start < x_end) { |
| int same_column = 1; |
| for (y = y_start; y <= y_end; y++) { |
| if (ref[y*ref_linesize + x_start] != buf[y*linesize + x_start]) { |
| same_column = 0; |
| break; |
| } |
| } |
| if (!same_column) |
| break; |
| x_start++; |
| } |
| while (x_end > x_start) { |
| int same_column = 1; |
| for (y = y_start; y <= y_end; y++) { |
| if (ref[y*ref_linesize + x_end] != buf[y*linesize + x_end]) { |
| same_column = 0; |
| break; |
| } |
| } |
| if (!same_column) |
| break; |
| x_end--; |
| } |
| width = x_end + 1 - x_start; |
| |
| av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d) [area:%dx%d]\n", |
| width, height, x_start, y_start, avctx->width, avctx->height); |
| } |
| |
| /* image block */ |
| bytestream_put_byte(bytestream, GIF_IMAGE_SEPARATOR); |
| bytestream_put_le16(bytestream, x_start); |
| bytestream_put_le16(bytestream, y_start); |
| bytestream_put_le16(bytestream, width); |
| bytestream_put_le16(bytestream, height); |
| |
| if (!palette) { |
| bytestream_put_byte(bytestream, 0x00); /* flags */ |
| } else { |
| unsigned i; |
| bytestream_put_byte(bytestream, 1<<7 | 0x7); /* flags */ |
| for (i = 0; i < AVPALETTE_COUNT; i++) { |
| const uint32_t v = palette[i]; |
| bytestream_put_be24(bytestream, v); |
| } |
| } |
| |
| if (honor_transparency && trans < 0) { |
| trans = pick_palette_entry(buf + y_start*linesize + x_start, |
| linesize, width, height); |
| if (trans < 0) { // TODO, patch welcome |
| av_log(avctx, AV_LOG_DEBUG, "No available color, can not use transparency\n"); |
| } else { |
| uint8_t *pal_exdata = s->pal_exdata; |
| if (!pal_exdata) |
| pal_exdata = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE); |
| if (!pal_exdata) |
| return AVERROR(ENOMEM); |
| memcpy(pal_exdata, s->palette, AVPALETTE_SIZE); |
| pal_exdata[trans*4 + 3*!HAVE_BIGENDIAN] = 0x00; |
| } |
| } |
| if (trans < 0) |
| honor_transparency = 0; |
| |
| bytestream_put_byte(bytestream, 0x08); |
| |
| ff_lzw_encode_init(s->lzw, s->buf, s->buf_size, |
| 12, FF_LZW_GIF, put_bits); |
| |
| ptr = buf + y_start*linesize + x_start; |
| if (honor_transparency) { |
| const int ref_linesize = s->last_frame->linesize[0]; |
| const uint8_t *ref = s->last_frame->data[0] + y_start*ref_linesize + x_start; |
| |
| for (y = 0; y < height; y++) { |
| memcpy(s->tmpl, ptr, width); |
| for (x = 0; x < width; x++) |
| if (ref[x] == ptr[x]) |
| s->tmpl[x] = trans; |
| len += ff_lzw_encode(s->lzw, s->tmpl, width); |
| ptr += linesize; |
| ref += ref_linesize; |
| } |
| } else { |
| for (y = 0; y < height; y++) { |
| len += ff_lzw_encode(s->lzw, ptr, width); |
| ptr += linesize; |
| } |
| } |
| len += ff_lzw_encode_flush(s->lzw, flush_put_bits); |
| |
| ptr = s->buf; |
| while (len > 0) { |
| int size = FFMIN(255, len); |
| bytestream_put_byte(bytestream, size); |
| if (end - *bytestream < size) |
| return -1; |
| bytestream_put_buffer(bytestream, ptr, size); |
| ptr += size; |
| len -= size; |
| } |
| bytestream_put_byte(bytestream, 0x00); /* end of image block */ |
| return 0; |
| } |
| |
| static av_cold int gif_encode_init(AVCodecContext *avctx) |
| { |
| GIFContext *s = avctx->priv_data; |
| |
| if (avctx->width > 65535 || avctx->height > 65535) { |
| av_log(avctx, AV_LOG_ERROR, "GIF does not support resolutions above 65535x65535\n"); |
| return AVERROR(EINVAL); |
| } |
| #if FF_API_CODED_FRAME |
| FF_DISABLE_DEPRECATION_WARNINGS |
| avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I; |
| avctx->coded_frame->key_frame = 1; |
| FF_ENABLE_DEPRECATION_WARNINGS |
| #endif |
| |
| s->transparent_index = -1; |
| |
| s->lzw = av_mallocz(ff_lzw_encode_state_size); |
| s->buf_size = avctx->width*avctx->height*2 + 1000; |
| s->buf = av_malloc(s->buf_size); |
| s->tmpl = av_malloc(avctx->width); |
| if (!s->tmpl || !s->buf || !s->lzw) |
| return AVERROR(ENOMEM); |
| |
| if (avpriv_set_systematic_pal2(s->palette, avctx->pix_fmt) < 0) |
| av_assert0(avctx->pix_fmt == AV_PIX_FMT_PAL8); |
| |
| return 0; |
| } |
| |
| /* FIXME: duplicated with lavc */ |
| static int get_palette_transparency_index(const uint32_t *palette) |
| { |
| int transparent_color_index = -1; |
| unsigned i, smallest_alpha = 0xff; |
| |
| if (!palette) |
| return -1; |
| |
| 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; |
| } |
| } |
| return smallest_alpha < 128 ? transparent_color_index : -1; |
| } |
| |
| static int gif_encode_frame(AVCodecContext *avctx, AVPacket *pkt, |
| const AVFrame *pict, int *got_packet) |
| { |
| GIFContext *s = avctx->priv_data; |
| uint8_t *outbuf_ptr, *end; |
| const uint32_t *palette = NULL; |
| int ret; |
| |
| if ((ret = ff_alloc_packet2(avctx, pkt, avctx->width*avctx->height*7/5 + AV_INPUT_BUFFER_MIN_SIZE, 0)) < 0) |
| return ret; |
| outbuf_ptr = pkt->data; |
| end = pkt->data + pkt->size; |
| |
| if (avctx->pix_fmt == AV_PIX_FMT_PAL8) { |
| uint8_t *pal_exdata = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE); |
| if (!pal_exdata) |
| return AVERROR(ENOMEM); |
| memcpy(pal_exdata, pict->data[1], AVPALETTE_SIZE); |
| palette = (uint32_t*)pict->data[1]; |
| |
| s->pal_exdata = pal_exdata; |
| |
| /* The first palette with PAL8 will be used as generic palette by the |
| * muxer so we don't need to write it locally in the packet. We store |
| * it as a reference here in case it changes later. */ |
| if (!s->palette_loaded) { |
| memcpy(s->palette, palette, AVPALETTE_SIZE); |
| s->transparent_index = get_palette_transparency_index(palette); |
| s->palette_loaded = 1; |
| palette = NULL; |
| } else if (!memcmp(s->palette, palette, AVPALETTE_SIZE)) { |
| palette = NULL; |
| } |
| } |
| |
| gif_image_write_image(avctx, &outbuf_ptr, end, palette, |
| pict->data[0], pict->linesize[0], pkt); |
| if (!s->last_frame) { |
| s->last_frame = av_frame_alloc(); |
| if (!s->last_frame) |
| return AVERROR(ENOMEM); |
| } |
| av_frame_unref(s->last_frame); |
| ret = av_frame_ref(s->last_frame, (AVFrame*)pict); |
| if (ret < 0) |
| return ret; |
| |
| pkt->size = outbuf_ptr - pkt->data; |
| pkt->flags |= AV_PKT_FLAG_KEY; |
| *got_packet = 1; |
| |
| return 0; |
| } |
| |
| static int gif_encode_close(AVCodecContext *avctx) |
| { |
| GIFContext *s = avctx->priv_data; |
| |
| av_freep(&s->lzw); |
| av_freep(&s->buf); |
| s->buf_size = 0; |
| av_frame_free(&s->last_frame); |
| av_freep(&s->tmpl); |
| return 0; |
| } |
| |
| #define OFFSET(x) offsetof(GIFContext, x) |
| #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM |
| static const AVOption gif_options[] = { |
| { "gifflags", "set GIF flags", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = GF_OFFSETTING|GF_TRANSDIFF}, 0, INT_MAX, FLAGS, "flags" }, |
| { "offsetting", "enable picture offsetting", 0, AV_OPT_TYPE_CONST, {.i64=GF_OFFSETTING}, INT_MIN, INT_MAX, FLAGS, "flags" }, |
| { "transdiff", "enable transparency detection between frames", 0, AV_OPT_TYPE_CONST, {.i64=GF_TRANSDIFF}, INT_MIN, INT_MAX, FLAGS, "flags" }, |
| { NULL } |
| }; |
| |
| static const AVClass gif_class = { |
| .class_name = "GIF encoder", |
| .item_name = av_default_item_name, |
| .option = gif_options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| AVCodec ff_gif_encoder = { |
| .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(GIFContext), |
| .init = gif_encode_init, |
| .encode2 = gif_encode_frame, |
| .close = gif_encode_close, |
| .pix_fmts = (const enum AVPixelFormat[]){ |
| AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE, |
| AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE |
| }, |
| .priv_class = &gif_class, |
| }; |
