yading@10: /* yading@10: * Copyright (c) 2000 Fabrice Bellard yading@10: * Copyright (c) 2002 Francois Revol yading@10: * Copyright (c) 2006 Baptiste Coudurier yading@10: * yading@10: * first version by Francois Revol yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: /** yading@10: * @file yading@10: * GIF encoder yading@10: * @see http://www.w3.org/Graphics/GIF/spec-gif89a.txt yading@10: */ yading@10: yading@10: #include "libavutil/opt.h" yading@10: #include "libavutil/imgutils.h" yading@10: #include "avcodec.h" yading@10: #include "bytestream.h" yading@10: #include "internal.h" yading@10: #include "lzw.h" yading@10: #include "gif.h" yading@10: yading@10: #define BITSTREAM_WRITER_LE yading@10: #include "put_bits.h" yading@10: yading@10: typedef struct { yading@10: const AVClass *class; yading@10: AVFrame picture; yading@10: LZWState *lzw; yading@10: uint8_t *buf; yading@10: AVFrame *last_frame; yading@10: int flags; yading@10: uint32_t palette[AVPALETTE_COUNT]; ///< local reference palette for !pal8 yading@10: uint8_t *tmpl; ///< temporary line buffer yading@10: } GIFContext; yading@10: yading@10: enum { yading@10: GF_OFFSETTING = 1<<0, yading@10: GF_TRANSDIFF = 1<<1, yading@10: }; yading@10: yading@10: static int pick_palette_entry(const uint8_t *buf, int linesize, int w, int h) yading@10: { yading@10: int histogram[AVPALETTE_COUNT] = {0}; yading@10: int x, y, i; yading@10: yading@10: for (y = 0; y < h; y++) { yading@10: for (x = 0; x < w; x++) yading@10: histogram[buf[x]]++; yading@10: buf += linesize; yading@10: } yading@10: for (i = 0; i < FF_ARRAY_ELEMS(histogram); i++) yading@10: if (!histogram[i]) yading@10: return i; yading@10: return -1; yading@10: } yading@10: yading@10: static int gif_image_write_image(AVCodecContext *avctx, yading@10: uint8_t **bytestream, uint8_t *end, yading@10: const uint32_t *palette, yading@10: const uint8_t *buf, const int linesize, yading@10: AVPacket *pkt) yading@10: { yading@10: GIFContext *s = avctx->priv_data; yading@10: int len = 0, height = avctx->height, width = avctx->width, x, y; yading@10: int x_start = 0, y_start = 0, trans = -1; yading@10: const uint8_t *ptr; yading@10: yading@10: /* Crop image */ yading@10: // TODO support with palette change yading@10: if ((s->flags & GF_OFFSETTING) && s->last_frame && !palette) { yading@10: const uint8_t *ref = s->last_frame->data[0]; yading@10: const int ref_linesize = s->last_frame->linesize[0]; yading@10: int x_end = avctx->width - 1, yading@10: y_end = avctx->height - 1; yading@10: yading@10: /* skip common lines */ yading@10: while (y_start < y_end) { yading@10: if (memcmp(ref + y_start*ref_linesize, buf + y_start*linesize, width)) yading@10: break; yading@10: y_start++; yading@10: } yading@10: while (y_end > y_start) { yading@10: if (memcmp(ref + y_end*ref_linesize, buf + y_end*linesize, width)) yading@10: break; yading@10: y_end--; yading@10: } yading@10: height = y_end + 1 - y_start; yading@10: yading@10: /* skip common columns */ yading@10: while (x_start < x_end) { yading@10: int same_column = 1; yading@10: for (y = y_start; y < y_end; y++) { yading@10: if (ref[y*ref_linesize + x_start] != buf[y*linesize + x_start]) { yading@10: same_column = 0; yading@10: break; yading@10: } yading@10: } yading@10: if (!same_column) yading@10: break; yading@10: x_start++; yading@10: } yading@10: while (x_end > x_start) { yading@10: int same_column = 1; yading@10: for (y = y_start; y < y_end; y++) { yading@10: if (ref[y*ref_linesize + x_end] != buf[y*linesize + x_end]) { yading@10: same_column = 0; yading@10: break; yading@10: } yading@10: } yading@10: if (!same_column) yading@10: break; yading@10: x_end--; yading@10: } yading@10: width = x_end + 1 - x_start; yading@10: yading@10: av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d) [area:%dx%d]\n", yading@10: width, height, x_start, y_start, avctx->width, avctx->height); yading@10: } yading@10: yading@10: /* image block */ yading@10: bytestream_put_byte(bytestream, GIF_IMAGE_SEPARATOR); yading@10: bytestream_put_le16(bytestream, x_start); yading@10: bytestream_put_le16(bytestream, y_start); yading@10: bytestream_put_le16(bytestream, width); yading@10: bytestream_put_le16(bytestream, height); yading@10: yading@10: if (!palette) { yading@10: bytestream_put_byte(bytestream, 0x00); /* flags */ yading@10: } else { yading@10: unsigned i; yading@10: bytestream_put_byte(bytestream, 1<<7 | 0x7); /* flags */ yading@10: for (i = 0; i < AVPALETTE_COUNT; i++) { yading@10: const uint32_t v = palette[i]; yading@10: bytestream_put_be24(bytestream, v); yading@10: } yading@10: } yading@10: yading@10: /* TODO: support with palette change (pal8) */ yading@10: if ((s->flags & GF_TRANSDIFF) && s->last_frame && !palette) { yading@10: trans = pick_palette_entry(buf + y_start*linesize + x_start, yading@10: linesize, width, height); yading@10: if (trans < 0) { // TODO, patch welcome yading@10: av_log(avctx, AV_LOG_DEBUG, "No available color, can not use transparency\n"); yading@10: } else { yading@10: uint8_t *pal_exdata = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE); yading@10: if (!pal_exdata) yading@10: return AVERROR(ENOMEM); yading@10: memcpy(pal_exdata, s->palette, AVPALETTE_SIZE); yading@10: pal_exdata[trans*4 + 3] = 0x00; yading@10: } yading@10: } yading@10: yading@10: bytestream_put_byte(bytestream, 0x08); yading@10: yading@10: ff_lzw_encode_init(s->lzw, s->buf, width * height, yading@10: 12, FF_LZW_GIF, put_bits); yading@10: yading@10: ptr = buf + y_start*linesize + x_start; yading@10: if (trans >= 0) { yading@10: const int ref_linesize = s->last_frame->linesize[0]; yading@10: const uint8_t *ref = s->last_frame->data[0] + y_start*ref_linesize + x_start; yading@10: yading@10: for (y = 0; y < height; y++) { yading@10: memcpy(s->tmpl, ptr, width); yading@10: for (x = 0; x < width; x++) yading@10: if (ref[x] == ptr[x]) yading@10: s->tmpl[x] = trans; yading@10: len += ff_lzw_encode(s->lzw, s->tmpl, width); yading@10: ptr += linesize; yading@10: ref += ref_linesize; yading@10: } yading@10: } else { yading@10: for (y = 0; y < height; y++) { yading@10: len += ff_lzw_encode(s->lzw, ptr, width); yading@10: ptr += linesize; yading@10: } yading@10: } yading@10: len += ff_lzw_encode_flush(s->lzw, flush_put_bits); yading@10: yading@10: ptr = s->buf; yading@10: while (len > 0) { yading@10: int size = FFMIN(255, len); yading@10: bytestream_put_byte(bytestream, size); yading@10: if (end - *bytestream < size) yading@10: return -1; yading@10: bytestream_put_buffer(bytestream, ptr, size); yading@10: ptr += size; yading@10: len -= size; yading@10: } yading@10: bytestream_put_byte(bytestream, 0x00); /* end of image block */ yading@10: return 0; yading@10: } yading@10: yading@10: static av_cold int gif_encode_init(AVCodecContext *avctx) yading@10: { yading@10: GIFContext *s = avctx->priv_data; yading@10: yading@10: if (avctx->width > 65535 || avctx->height > 65535) { yading@10: av_log(avctx, AV_LOG_ERROR, "GIF does not support resolutions above 65535x65535\n"); yading@10: return AVERROR(EINVAL); yading@10: } yading@10: yading@10: avctx->coded_frame = &s->picture; yading@10: s->lzw = av_mallocz(ff_lzw_encode_state_size); yading@10: s->buf = av_malloc(avctx->width*avctx->height*2); yading@10: s->tmpl = av_malloc(avctx->width); yading@10: if (!s->tmpl || !s->buf || !s->lzw) yading@10: return AVERROR(ENOMEM); yading@10: yading@10: if (avpriv_set_systematic_pal2(s->palette, avctx->pix_fmt) < 0) yading@10: av_assert0(avctx->pix_fmt == AV_PIX_FMT_PAL8); yading@10: yading@10: return 0; yading@10: } yading@10: yading@10: static int gif_encode_frame(AVCodecContext *avctx, AVPacket *pkt, yading@10: const AVFrame *pict, int *got_packet) yading@10: { yading@10: GIFContext *s = avctx->priv_data; yading@10: AVFrame *const p = &s->picture; yading@10: uint8_t *outbuf_ptr, *end; yading@10: const uint32_t *palette = NULL; yading@10: int ret; yading@10: yading@10: if ((ret = ff_alloc_packet2(avctx, pkt, avctx->width*avctx->height*7/5 + FF_MIN_BUFFER_SIZE)) < 0) yading@10: return ret; yading@10: outbuf_ptr = pkt->data; yading@10: end = pkt->data + pkt->size; yading@10: yading@10: *p = *pict; yading@10: p->pict_type = AV_PICTURE_TYPE_I; yading@10: p->key_frame = 1; yading@10: yading@10: if (avctx->pix_fmt == AV_PIX_FMT_PAL8) { yading@10: uint8_t *pal_exdata = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE); yading@10: if (!pal_exdata) yading@10: return AVERROR(ENOMEM); yading@10: memcpy(pal_exdata, p->data[1], AVPALETTE_SIZE); yading@10: palette = (uint32_t*)p->data[1]; yading@10: } yading@10: yading@10: gif_image_write_image(avctx, &outbuf_ptr, end, palette, yading@10: pict->data[0], pict->linesize[0], pkt); yading@10: if (!s->last_frame) { yading@10: s->last_frame = av_frame_alloc(); yading@10: if (!s->last_frame) yading@10: return AVERROR(ENOMEM); yading@10: } yading@10: av_frame_unref(s->last_frame); yading@10: ret = av_frame_ref(s->last_frame, (AVFrame*)pict); yading@10: if (ret < 0) yading@10: return ret; yading@10: yading@10: pkt->size = outbuf_ptr - pkt->data; yading@10: pkt->flags |= AV_PKT_FLAG_KEY; yading@10: *got_packet = 1; yading@10: yading@10: return 0; yading@10: } yading@10: yading@10: static int gif_encode_close(AVCodecContext *avctx) yading@10: { yading@10: GIFContext *s = avctx->priv_data; yading@10: yading@10: av_freep(&s->lzw); yading@10: av_freep(&s->buf); yading@10: av_frame_free(&s->last_frame); yading@10: av_freep(&s->tmpl); yading@10: return 0; yading@10: } yading@10: yading@10: #define OFFSET(x) offsetof(GIFContext, x) yading@10: #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM yading@10: static const AVOption gif_options[] = { yading@10: { "gifflags", "set GIF flags", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = GF_OFFSETTING|GF_TRANSDIFF}, 0, INT_MAX, FLAGS, "flags" }, yading@10: { "offsetting", "enable picture offsetting", 0, AV_OPT_TYPE_CONST, {.i64=GF_OFFSETTING}, INT_MIN, INT_MAX, FLAGS, "flags" }, yading@10: { "transdiff", "enable transparency detection between frames", 0, AV_OPT_TYPE_CONST, {.i64=GF_TRANSDIFF}, INT_MIN, INT_MAX, FLAGS, "flags" }, yading@10: { NULL } yading@10: }; yading@10: yading@10: static const AVClass gif_class = { yading@10: .class_name = "GIF encoder", yading@10: .item_name = av_default_item_name, yading@10: .option = gif_options, yading@10: .version = LIBAVUTIL_VERSION_INT, yading@10: }; yading@10: yading@10: AVCodec ff_gif_encoder = { yading@10: .name = "gif", yading@10: .type = AVMEDIA_TYPE_VIDEO, yading@10: .id = AV_CODEC_ID_GIF, yading@10: .priv_data_size = sizeof(GIFContext), yading@10: .init = gif_encode_init, yading@10: .encode2 = gif_encode_frame, yading@10: .close = gif_encode_close, yading@10: .pix_fmts = (const enum AVPixelFormat[]){ yading@10: AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE, yading@10: AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE yading@10: }, yading@10: .long_name = NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"), yading@10: .priv_class = &gif_class, yading@10: };