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Diffstat (limited to 'contrib/ffmpeg/libavcodec/pngenc.c')
-rw-r--r--contrib/ffmpeg/libavcodec/pngenc.c448
1 files changed, 448 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/pngenc.c b/contrib/ffmpeg/libavcodec/pngenc.c
new file mode 100644
index 000000000..703371d85
--- /dev/null
+++ b/contrib/ffmpeg/libavcodec/pngenc.c
@@ -0,0 +1,448 @@
+/*
+ * PNG image format
+ * Copyright (c) 2003 Fabrice Bellard.
+ *
+ * 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 "avcodec.h"
+#include "bytestream.h"
+#include "png.h"
+#include <dsputil.h>
+
+/* TODO:
+ * - add 2, 4 and 16 bit depth support
+ */
+
+#include <zlib.h>
+
+//#define DEBUG
+
+#define IOBUF_SIZE 4096
+
+typedef struct PNGEncContext {
+ DSPContext dsp;
+
+ uint8_t *bytestream;
+ uint8_t *bytestream_start;
+ uint8_t *bytestream_end;
+ AVFrame picture;
+
+ int filter_type;
+
+ z_stream zstream;
+ uint8_t buf[IOBUF_SIZE];
+} PNGEncContext;
+
+static void png_get_interlaced_row(uint8_t *dst, int row_size,
+ int bits_per_pixel, int pass,
+ const uint8_t *src, int width)
+{
+ int x, mask, dst_x, j, b, bpp;
+ uint8_t *d;
+ const uint8_t *s;
+
+ mask = ff_png_pass_mask[pass];
+ switch(bits_per_pixel) {
+ case 1:
+ memset(dst, 0, row_size);
+ dst_x = 0;
+ for(x = 0; x < width; x++) {
+ j = (x & 7);
+ if ((mask << j) & 0x80) {
+ b = (src[x >> 3] >> (7 - j)) & 1;
+ dst[dst_x >> 3] |= b << (7 - (dst_x & 7));
+ dst_x++;
+ }
+ }
+ break;
+ default:
+ bpp = bits_per_pixel >> 3;
+ d = dst;
+ s = src;
+ for(x = 0; x < width; x++) {
+ j = x & 7;
+ if ((mask << j) & 0x80) {
+ memcpy(d, s, bpp);
+ d += bpp;
+ }
+ s += bpp;
+ }
+ break;
+ }
+}
+
+static void sub_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
+{
+ int i;
+ for(i = 0; i < w; i++) {
+ int a, b, c, p, pa, pb, pc;
+
+ a = src[i - bpp];
+ b = top[i];
+ c = top[i - bpp];
+
+ p = b - c;
+ pc = a - c;
+
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+
+ if (pa <= pb && pa <= pc)
+ p = a;
+ else if (pb <= pc)
+ p = b;
+ else
+ p = c;
+ dst[i] = src[i] - p;
+ }
+}
+
+static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
+ uint8_t *src, uint8_t *top, int size, int bpp)
+{
+ int i;
+
+ switch(filter_type) {
+ case PNG_FILTER_VALUE_NONE:
+ memcpy(dst, src, size);
+ break;
+ case PNG_FILTER_VALUE_SUB:
+ dsp->diff_bytes(dst, src, src-bpp, size);
+ memcpy(dst, src, bpp);
+ break;
+ case PNG_FILTER_VALUE_UP:
+ dsp->diff_bytes(dst, src, top, size);
+ break;
+ case PNG_FILTER_VALUE_AVG:
+ for(i = 0; i < bpp; i++)
+ dst[i] = src[i] - (top[i] >> 1);
+ for(; i < size; i++)
+ dst[i] = src[i] - ((src[i-bpp] + top[i]) >> 1);
+ break;
+ case PNG_FILTER_VALUE_PAETH:
+ for(i = 0; i < bpp; i++)
+ dst[i] = src[i] - top[i];
+ sub_png_paeth_prediction(dst+i, src+i, top+i, size-i, bpp);
+ break;
+ }
+}
+
+static uint8_t *png_choose_filter(PNGEncContext *s, uint8_t *dst,
+ uint8_t *src, uint8_t *top, int size, int bpp)
+{
+ int pred = s->filter_type;
+ assert(bpp || !pred);
+ if(!top && pred)
+ pred = PNG_FILTER_VALUE_SUB;
+ if(pred == PNG_FILTER_VALUE_MIXED) {
+ int i;
+ int cost, bcost = INT_MAX;
+ uint8_t *buf1 = dst, *buf2 = dst + size + 16;
+ for(pred=0; pred<5; pred++) {
+ png_filter_row(&s->dsp, buf1+1, pred, src, top, size, bpp);
+ buf1[0] = pred;
+ cost = 0;
+ for(i=0; i<=size; i++)
+ cost += abs((int8_t)buf1[i]);
+ if(cost < bcost) {
+ bcost = cost;
+ FFSWAP(uint8_t*, buf1, buf2);
+ }
+ }
+ return buf2;
+ } else {
+ png_filter_row(&s->dsp, dst+1, pred, src, top, size, bpp);
+ dst[0] = pred;
+ return dst;
+ }
+}
+
+static void convert_from_rgb32(uint8_t *dst, const uint8_t *src, int width)
+{
+ uint8_t *d;
+ int j;
+ unsigned int v;
+
+ d = dst;
+ for(j = 0; j < width; j++) {
+ v = ((const uint32_t *)src)[j];
+ d[0] = v >> 16;
+ d[1] = v >> 8;
+ d[2] = v;
+ d[3] = v >> 24;
+ d += 4;
+ }
+}
+
+static void png_write_chunk(uint8_t **f, uint32_t tag,
+ const uint8_t *buf, int length)
+{
+ uint32_t crc;
+ uint8_t tagbuf[4];
+
+ bytestream_put_be32(f, length);
+ crc = crc32(0, Z_NULL, 0);
+ AV_WL32(tagbuf, tag);
+ crc = crc32(crc, tagbuf, 4);
+ bytestream_put_be32(f, bswap_32(tag));
+ if (length > 0) {
+ crc = crc32(crc, buf, length);
+ memcpy(*f, buf, length);
+ *f += length;
+ }
+ bytestream_put_be32(f, crc);
+}
+
+/* XXX: do filtering */
+static int png_write_row(PNGEncContext *s, const uint8_t *data, int size)
+{
+ int ret;
+
+ s->zstream.avail_in = size;
+ s->zstream.next_in = (uint8_t *)data;
+ while (s->zstream.avail_in > 0) {
+ ret = deflate(&s->zstream, Z_NO_FLUSH);
+ if (ret != Z_OK)
+ return -1;
+ if (s->zstream.avail_out == 0) {
+ if(s->bytestream_end - s->bytestream > IOBUF_SIZE + 100)
+ png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, IOBUF_SIZE);
+ s->zstream.avail_out = IOBUF_SIZE;
+ s->zstream.next_out = s->buf;
+ }
+ }
+ return 0;
+}
+
+static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
+ PNGEncContext *s = avctx->priv_data;
+ AVFrame *pict = data;
+ AVFrame * const p= (AVFrame*)&s->picture;
+ int bit_depth, color_type, y, len, row_size, ret, is_progressive;
+ int bits_per_pixel, pass_row_size;
+ int compression_level;
+ uint8_t *ptr, *top;
+ uint8_t *crow_base = NULL, *crow_buf, *crow;
+ uint8_t *progressive_buf = NULL;
+ uint8_t *rgba_buf = NULL;
+ uint8_t *top_buf = NULL;
+
+ *p = *pict;
+ p->pict_type= FF_I_TYPE;
+ p->key_frame= 1;
+
+ s->bytestream_start=
+ s->bytestream= buf;
+ s->bytestream_end= buf+buf_size;
+
+ is_progressive = !!(avctx->flags & CODEC_FLAG_INTERLACED_DCT);
+ switch(avctx->pix_fmt) {
+ case PIX_FMT_RGB32:
+ bit_depth = 8;
+ color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+ break;
+ case PIX_FMT_RGB24:
+ bit_depth = 8;
+ color_type = PNG_COLOR_TYPE_RGB;
+ break;
+ case PIX_FMT_GRAY8:
+ bit_depth = 8;
+ color_type = PNG_COLOR_TYPE_GRAY;
+ break;
+ case PIX_FMT_MONOBLACK:
+ bit_depth = 1;
+ color_type = PNG_COLOR_TYPE_GRAY;
+ break;
+ case PIX_FMT_PAL8:
+ bit_depth = 8;
+ color_type = PNG_COLOR_TYPE_PALETTE;
+ break;
+ default:
+ return -1;
+ }
+ bits_per_pixel = ff_png_get_nb_channels(color_type) * bit_depth;
+ row_size = (avctx->width * bits_per_pixel + 7) >> 3;
+
+ s->zstream.zalloc = ff_png_zalloc;
+ s->zstream.zfree = ff_png_zfree;
+ s->zstream.opaque = NULL;
+ compression_level = avctx->compression_level == FF_COMPRESSION_DEFAULT ?
+ Z_DEFAULT_COMPRESSION :
+ av_clip(avctx->compression_level, 0, 9);
+ ret = deflateInit2(&s->zstream, compression_level,
+ Z_DEFLATED, 15, 8, Z_DEFAULT_STRATEGY);
+ if (ret != Z_OK)
+ return -1;
+ crow_base = av_malloc((row_size + 32) << (s->filter_type == PNG_FILTER_VALUE_MIXED));
+ if (!crow_base)
+ goto fail;
+ crow_buf = crow_base + 15; // pixel data should be aligned, but there's a control byte before it
+ if (is_progressive) {
+ progressive_buf = av_malloc(row_size + 1);
+ if (!progressive_buf)
+ goto fail;
+ }
+ if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
+ rgba_buf = av_malloc(row_size + 1);
+ if (!rgba_buf)
+ goto fail;
+ }
+ if (is_progressive || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
+ top_buf = av_malloc(row_size + 1);
+ if (!top_buf)
+ goto fail;
+ }
+
+ /* write png header */
+ memcpy(s->bytestream, ff_pngsig, 8);
+ s->bytestream += 8;
+
+ AV_WB32(s->buf, avctx->width);
+ AV_WB32(s->buf + 4, avctx->height);
+ s->buf[8] = bit_depth;
+ s->buf[9] = color_type;
+ s->buf[10] = 0; /* compression type */
+ s->buf[11] = 0; /* filter type */
+ s->buf[12] = is_progressive; /* interlace type */
+
+ png_write_chunk(&s->bytestream, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);
+
+ /* put the palette if needed */
+ if (color_type == PNG_COLOR_TYPE_PALETTE) {
+ int has_alpha, alpha, i;
+ unsigned int v;
+ uint32_t *palette;
+ uint8_t *alpha_ptr;
+
+ palette = (uint32_t *)p->data[1];
+ ptr = s->buf;
+ alpha_ptr = s->buf + 256 * 3;
+ has_alpha = 0;
+ for(i = 0; i < 256; i++) {
+ v = palette[i];
+ alpha = v >> 24;
+ if (alpha && alpha != 0xff)
+ has_alpha = 1;
+ *alpha_ptr++ = alpha;
+ bytestream_put_be24(&ptr, v);
+ }
+ png_write_chunk(&s->bytestream, MKTAG('P', 'L', 'T', 'E'), s->buf, 256 * 3);
+ if (has_alpha) {
+ png_write_chunk(&s->bytestream, MKTAG('t', 'R', 'N', 'S'), s->buf + 256 * 3, 256);
+ }
+ }
+
+ /* now put each row */
+ s->zstream.avail_out = IOBUF_SIZE;
+ s->zstream.next_out = s->buf;
+ if (is_progressive) {
+ int pass;
+
+ for(pass = 0; pass < NB_PASSES; pass++) {
+ /* NOTE: a pass is completely omited if no pixels would be
+ output */
+ pass_row_size = ff_png_pass_row_size(pass, bits_per_pixel, avctx->width);
+ if (pass_row_size > 0) {
+ top = NULL;
+ for(y = 0; y < avctx->height; y++) {
+ if ((ff_png_pass_ymask[pass] << (y & 7)) & 0x80) {
+ ptr = p->data[0] + y * p->linesize[0];
+ FFSWAP(uint8_t*, progressive_buf, top_buf);
+ if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
+ convert_from_rgb32(rgba_buf, ptr, avctx->width);
+ ptr = rgba_buf;
+ }
+ png_get_interlaced_row(progressive_buf, pass_row_size,
+ bits_per_pixel, pass,
+ ptr, avctx->width);
+ crow = png_choose_filter(s, crow_buf, progressive_buf, top, pass_row_size, bits_per_pixel>>3);
+ png_write_row(s, crow, pass_row_size + 1);
+ top = progressive_buf;
+ }
+ }
+ }
+ }
+ } else {
+ top = NULL;
+ for(y = 0; y < avctx->height; y++) {
+ ptr = p->data[0] + y * p->linesize[0];
+ if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
+ FFSWAP(uint8_t*, rgba_buf, top_buf);
+ convert_from_rgb32(rgba_buf, ptr, avctx->width);
+ ptr = rgba_buf;
+ }
+ crow = png_choose_filter(s, crow_buf, ptr, top, row_size, bits_per_pixel>>3);
+ png_write_row(s, crow, row_size + 1);
+ top = ptr;
+ }
+ }
+ /* compress last bytes */
+ for(;;) {
+ ret = deflate(&s->zstream, Z_FINISH);
+ if (ret == Z_OK || ret == Z_STREAM_END) {
+ len = IOBUF_SIZE - s->zstream.avail_out;
+ if (len > 0 && s->bytestream_end - s->bytestream > len + 100) {
+ png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, len);
+ }
+ s->zstream.avail_out = IOBUF_SIZE;
+ s->zstream.next_out = s->buf;
+ if (ret == Z_STREAM_END)
+ break;
+ } else {
+ goto fail;
+ }
+ }
+ png_write_chunk(&s->bytestream, MKTAG('I', 'E', 'N', 'D'), NULL, 0);
+
+ ret = s->bytestream - s->bytestream_start;
+ the_end:
+ av_free(crow_base);
+ av_free(progressive_buf);
+ av_free(rgba_buf);
+ av_free(top_buf);
+ deflateEnd(&s->zstream);
+ return ret;
+ fail:
+ ret = -1;
+ goto the_end;
+}
+
+static int png_enc_init(AVCodecContext *avctx){
+ PNGEncContext *s = avctx->priv_data;
+
+ avcodec_get_frame_defaults((AVFrame*)&s->picture);
+ avctx->coded_frame= (AVFrame*)&s->picture;
+ dsputil_init(&s->dsp, avctx);
+
+ s->filter_type = av_clip(avctx->prediction_method, PNG_FILTER_VALUE_NONE, PNG_FILTER_VALUE_MIXED);
+ if(avctx->pix_fmt == PIX_FMT_MONOBLACK)
+ s->filter_type = PNG_FILTER_VALUE_NONE;
+
+ return 0;
+}
+
+AVCodec png_encoder = {
+ "png",
+ CODEC_TYPE_VIDEO,
+ CODEC_ID_PNG,
+ sizeof(PNGEncContext),
+ png_enc_init,
+ encode_frame,
+ NULL, //encode_end,
+ .pix_fmts= (enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGB32, PIX_FMT_PAL8, PIX_FMT_GRAY8, PIX_FMT_MONOBLACK, -1},
+};
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-27 13:10:33 +0000