0,0 → 1,316 |
/* |
* 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 { |
const AVClass *class; |
LZWState *lzw; |
uint8_t *buf; |
AVFrame *last_frame; |
int flags; |
uint32_t palette[AVPALETTE_COUNT]; ///< local reference palette for !pal8 |
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 = -1; |
const uint8_t *ptr; |
|
/* Crop image */ |
// TODO support with palette change |
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); |
} |
} |
|
/* TODO: support with palette change (pal8) */ |
if ((s->flags & GF_TRANSDIFF) && s->last_frame && !palette) { |
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 = 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; |
} |
} |
|
bytestream_put_byte(bytestream, 0x08); |
|
ff_lzw_encode_init(s->lzw, s->buf, 2 * width * height, |
12, FF_LZW_GIF, put_bits); |
|
ptr = buf + y_start*linesize + x_start; |
if (trans >= 0) { |
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); |
} |
|
s->lzw = av_mallocz(ff_lzw_encode_state_size); |
s->buf = av_malloc(avctx->width*avctx->height*2); |
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; |
} |
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static int gif_encode_frame(AVCodecContext *avctx, AVPacket *pkt, |
const AVFrame *pict, int *got_packet) |
{ |
GIFContext *s = avctx->priv_data; |
AVFrame *const p = (AVFrame *)pict; |
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 + FF_MIN_BUFFER_SIZE)) < 0) |
return ret; |
outbuf_ptr = pkt->data; |
end = pkt->data + pkt->size; |
|
p->pict_type = AV_PICTURE_TYPE_I; |
p->key_frame = 1; |
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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, p->data[1], AVPALETTE_SIZE); |
palette = (uint32_t*)p->data[1]; |
} |
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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; |
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pkt->size = outbuf_ptr - pkt->data; |
pkt->flags |= AV_PKT_FLAG_KEY; |
*got_packet = 1; |
|
return 0; |
} |
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static int gif_encode_close(AVCodecContext *avctx) |
{ |
GIFContext *s = avctx->priv_data; |
|
av_freep(&s->lzw); |
av_freep(&s->buf); |
av_frame_free(&s->last_frame); |
av_freep(&s->tmpl); |
return 0; |
} |
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#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, |
}; |