svq1: replace struct svq1_frame_size with an array.
[ffmpeg.git] / libavcodec / pngdec.c
index 037c5a0..b4e1fae 100644 (file)
@@ -2,26 +2,28 @@
  * PNG image format
  * Copyright (c) 2003 Fabrice Bellard
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
+#include "libavutil/imgutils.h"
 #include "avcodec.h"
 #include "bytestream.h"
+#include "internal.h"
 #include "png.h"
-#include "dsputil.h"
+#include "pngdsp.h"
 
 /* TODO:
  * - add 2, 4 and 16 bit depth support
 //#define DEBUG
 
 typedef struct PNGDecContext {
-    DSPContext dsp;
+    PNGDSPContext dsp;
 
-    const uint8_t *bytestream;
-    const uint8_t *bytestream_start;
-    const uint8_t *bytestream_end;
+    GetByteContext gb;
     AVFrame picture1, picture2;
     AVFrame *current_picture, *last_picture;
 
@@ -86,15 +86,16 @@ static void png_put_interlaced_row(uint8_t *dst, int width,
     uint8_t *d;
     const uint8_t *s;
 
-    mask = ff_png_pass_mask[pass];
+    mask     = ff_png_pass_mask[pass];
     dsp_mask = png_pass_dsp_mask[pass];
-    switch(bits_per_pixel) {
+
+    switch (bits_per_pixel) {
     case 1:
         /* we must initialize the line to zero before writing to it */
         if (pass == 0)
             memset(dst, 0, (width + 7) >> 3);
         src_x = 0;
-        for(x = 0; x < width; x++) {
+        for (x = 0; x < width; x++) {
             j = (x & 7);
             if ((dsp_mask << j) & 0x80) {
                 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
@@ -106,10 +107,10 @@ static void png_put_interlaced_row(uint8_t *dst, int width,
         break;
     default:
         bpp = bits_per_pixel >> 3;
-        d = dst;
-        s = src;
+        d   = dst;
+        s   = src;
         if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
-            for(x = 0; x < width; x++) {
+            for (x = 0; x < width; x++) {
                 j = x & 7;
                 if ((dsp_mask << j) & 0x80) {
                     *(uint32_t *)d = (s[3] << 24) | (s[0] << 16) | (s[1] << 8) | s[2];
@@ -136,14 +137,14 @@ static void png_put_interlaced_row(uint8_t *dst, int width,
 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
 {
     int i;
-    for(i = 0; i < w; i++) {
+    for (i = 0; i < w; i++) {
         int a, b, c, p, pa, pb, pc;
 
         a = dst[i - bpp];
         b = top[i];
         c = top[i - bpp];
 
-        p = b - c;
+        p  = b - c;
         pc = a - c;
 
         pa = abs(p);
@@ -190,25 +191,25 @@ void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w
     }
 
 /* NOTE: 'dst' can be equal to 'last' */
-static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
+static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
                            uint8_t *src, uint8_t *last, int size, int bpp)
 {
     int i, p, r, g, b, a;
 
-    switch(filter_type) {
+    switch (filter_type) {
     case PNG_FILTER_VALUE_NONE:
         memcpy(dst, src, size);
         break;
     case PNG_FILTER_VALUE_SUB:
-        for(i = 0; i < bpp; i++) {
+        for (i = 0; i < bpp; i++) {
             dst[i] = src[i];
         }
-        if(bpp == 4) {
+        if (bpp == 4) {
             p = *(int*)dst;
-            for(; i < size; i+=bpp) {
-                int s = *(int*)(src+i);
-                p = ((s&0x7f7f7f7f) + (p&0x7f7f7f7f)) ^ ((s^p)&0x80808080);
-                *(int*)(dst+i) = p;
+            for (; i < size; i += bpp) {
+                int s = *(int*)(src + i);
+                p = ((s & 0x7f7f7f7f) + (p & 0x7f7f7f7f)) ^ ((s ^ p) & 0x80808080);
+                *(int*)(dst + i) = p;
             }
         } else {
 #define OP_SUB(x,s,l) x+s
@@ -219,7 +220,7 @@ static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
         dsp->add_bytes_l2(dst, src, last, size);
         break;
     case PNG_FILTER_VALUE_AVG:
-        for(i = 0; i < bpp; i++) {
+        for (i = 0; i < bpp; i++) {
             p = (last[i] >> 1);
             dst[i] = p + src[i];
         }
@@ -227,34 +228,36 @@ static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
         UNROLL_FILTER(OP_AVG);
         break;
     case PNG_FILTER_VALUE_PAETH:
-        for(i = 0; i < bpp; i++) {
+        for (i = 0; i < bpp; i++) {
             p = last[i];
             dst[i] = p + src[i];
         }
-        if(bpp > 1 && size > 4) {
+        if (bpp > 1 && size > 4) {
             // would write off the end of the array if we let it process the last pixel with bpp=3
-            int w = bpp==4 ? size : size-3;
-            dsp->add_png_paeth_prediction(dst+i, src+i, last+i, w-i, bpp);
+            int w = bpp == 4 ? size : size - 3;
+            dsp->add_paeth_prediction(dst + i, src + i, last + i, w - i, bpp);
             i = w;
         }
-        ff_add_png_paeth_prediction(dst+i, src+i, last+i, size-i, bpp);
+        ff_add_png_paeth_prediction(dst + i, src + i, last + i, size - i, bpp);
         break;
     }
 }
 
-static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, const uint8_t *src, int width, int loco)
+static av_always_inline void convert_to_rgb32_loco(uint8_t *dst,
+                                                   const uint8_t *src,
+                                                   int width, int loco)
 {
     int j;
     unsigned int r, g, b, a;
 
-    for(j = 0;j < width; j++) {
+    for (j = 0; j < width; j++) {
         r = src[0];
         g = src[1];
         b = src[2];
         a = src[3];
-        if(loco) {
-            r = (r+g)&0xff;
-            b = (b+g)&0xff;
+        if (loco) {
+            r = (r + g) & 0xff;
+            b = (b + g) & 0xff;
         }
         *(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b;
         dst += 4;
@@ -264,7 +267,7 @@ static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, const uint8_t *
 
 static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width, int loco)
 {
-    if(loco)
+    if (loco)
         convert_to_rgb32_loco(dst, src, width, 1);
     else
         convert_to_rgb32_loco(dst, src, width, 0);
@@ -273,10 +276,10 @@ static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width, int lo
 static void deloco_rgb24(uint8_t *dst, int size)
 {
     int i;
-    for(i=0; i<size; i+=3) {
-        int g = dst[i+1];
-        dst[i+0] += g;
-        dst[i+2] += g;
+    for (i = 0; i < size; i += 3) {
+        int g = dst[i + 1];
+        dst[i + 0] += g;
+        dst[i + 2] += g;
     }
 }
 
@@ -317,7 +320,7 @@ static void png_handle_row(PNGDecContext *s)
         }
     } else {
         got_line = 0;
-        for(;;) {
+        for (;;) {
             ptr = s->image_buf + s->image_linesize * s->y;
             if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
                 /* if we already read one row, it is time to stop to
@@ -336,7 +339,7 @@ static void png_handle_row(PNGDecContext *s)
             }
             s->y++;
             if (s->y == s->height) {
-                for(;;) {
+                for (;;) {
                     if (s->pass == NB_PASSES - 1) {
                         s->state |= PNG_ALLIMAGE;
                         goto the_end;
@@ -361,12 +364,9 @@ static void png_handle_row(PNGDecContext *s)
 static int png_decode_idat(PNGDecContext *s, int length)
 {
     int ret;
-    s->zstream.avail_in = length;
-    s->zstream.next_in = s->bytestream;
-    s->bytestream += length;
-
-    if(s->bytestream > s->bytestream_end)
-        return -1;
+    s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb));
+    s->zstream.next_in  = s->gb.buffer;
+    bytestream2_skip(&s->gb, length);
 
     /* decode one line if possible */
     while (s->zstream.avail_in > 0) {
@@ -379,80 +379,76 @@ static int png_decode_idat(PNGDecContext *s, int length)
                 png_handle_row(s);
             }
             s->zstream.avail_out = s->crow_size;
-            s->zstream.next_out = s->crow_buf;
+            s->zstream.next_out  = s->crow_buf;
         }
     }
     return 0;
 }
 
 static int decode_frame(AVCodecContext *avctx,
-                        void *data, int *data_size,
+                        void *data, int *got_frame,
                         AVPacket *avpkt)
 {
-    const uint8_t *buf = avpkt->data;
-    int buf_size = avpkt->size;
     PNGDecContext * const s = avctx->priv_data;
-    AVFrame *picture = data;
+    const uint8_t *buf      = avpkt->data;
+    int buf_size            = avpkt->size;
+    AVFrame *picture        = data;
+    uint8_t *crow_buf_base  = NULL;
     AVFrame *p;
-    uint8_t *crow_buf_base = NULL;
     uint32_t tag, length;
-    int ret, crc;
+    int ret;
 
     FFSWAP(AVFrame *, s->current_picture, s->last_picture);
-    avctx->coded_frame= s->current_picture;
+    avctx->coded_frame = s->current_picture;
     p = s->current_picture;
 
-    s->bytestream_start=
-    s->bytestream= buf;
-    s->bytestream_end= buf + buf_size;
-
     /* check signature */
-    if (memcmp(s->bytestream, ff_pngsig, 8) != 0 &&
-        memcmp(s->bytestream, ff_mngsig, 8) != 0)
+    if (buf_size < 8 ||
+        memcmp(buf, ff_pngsig, 8) != 0 &&
+        memcmp(buf, ff_mngsig, 8) != 0)
         return -1;
-    s->bytestream+= 8;
-    s->y=
-    s->state=0;
-//    memset(s, 0, sizeof(PNGDecContext));
+
+    bytestream2_init(&s->gb, buf + 8, buf_size - 8);
+    s->y = s->state = 0;
+
     /* init the zlib */
     s->zstream.zalloc = ff_png_zalloc;
-    s->zstream.zfree = ff_png_zfree;
+    s->zstream.zfree  = ff_png_zfree;
     s->zstream.opaque = NULL;
     ret = inflateInit(&s->zstream);
     if (ret != Z_OK)
         return -1;
-    for(;;) {
-        int tag32;
-        if (s->bytestream >= s->bytestream_end)
+    for (;;) {
+        if (bytestream2_get_bytes_left(&s->gb) <= 0)
             goto fail;
-        length = bytestream_get_be32(&s->bytestream);
+        length = bytestream2_get_be32(&s->gb);
         if (length > 0x7fffffff)
             goto fail;
-        tag32 = bytestream_get_be32(&s->bytestream);
-        tag = av_bswap32(tag32);
-        dprintf(avctx, "png: tag=%c%c%c%c length=%u\n",
+        tag = bytestream2_get_le32(&s->gb);
+        av_dlog(avctx, "png: tag=%c%c%c%c length=%u\n",
                 (tag & 0xff),
                 ((tag >> 8) & 0xff),
                 ((tag >> 16) & 0xff),
                 ((tag >> 24) & 0xff), length);
-        switch(tag) {
+        switch (tag) {
         case MKTAG('I', 'H', 'D', 'R'):
             if (length != 13)
                 goto fail;
-            s->width = bytestream_get_be32(&s->bytestream);
-            s->height = bytestream_get_be32(&s->bytestream);
-            if(avcodec_check_dimensions(avctx, s->width, s->height)){
-                s->width= s->height= 0;
+            s->width  = bytestream2_get_be32(&s->gb);
+            s->height = bytestream2_get_be32(&s->gb);
+            if (av_image_check_size(s->width, s->height, 0, avctx)) {
+                s->width = s->height = 0;
                 goto fail;
             }
-            s->bit_depth = *s->bytestream++;
-            s->color_type = *s->bytestream++;
-            s->compression_type = *s->bytestream++;
-            s->filter_type = *s->bytestream++;
-            s->interlace_type = *s->bytestream++;
-            crc = bytestream_get_be32(&s->bytestream);
+            s->bit_depth        = bytestream2_get_byte(&s->gb);
+            s->color_type       = bytestream2_get_byte(&s->gb);
+            s->compression_type = bytestream2_get_byte(&s->gb);
+            s->filter_type      = bytestream2_get_byte(&s->gb);
+            s->interlace_type   = bytestream2_get_byte(&s->gb);
+            bytestream2_skip(&s->gb, 4); /* crc */
             s->state |= PNG_IHDR;
-            dprintf(avctx, "width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n",
+            av_dlog(avctx, "width=%d height=%d depth=%d color_type=%d "
+                    "compression_type=%d filter_type=%d interlace_type=%d\n",
                     s->width, s->height, s->bit_depth, s->color_type,
                     s->compression_type, s->filter_type, s->interlace_type);
             break;
@@ -461,49 +457,51 @@ static int decode_frame(AVCodecContext *avctx,
                 goto fail;
             if (!(s->state & PNG_IDAT)) {
                 /* init image info */
-                avctx->width = s->width;
+                avctx->width  = s->width;
                 avctx->height = s->height;
 
-                s->channels = ff_png_get_nb_channels(s->color_type);
+                s->channels       = ff_png_get_nb_channels(s->color_type);
                 s->bits_per_pixel = s->bit_depth * s->channels;
-                s->bpp = (s->bits_per_pixel + 7) >> 3;
-                s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
+                s->bpp            = (s->bits_per_pixel + 7) >> 3;
+                s->row_size       = (avctx->width * s->bits_per_pixel + 7) >> 3;
 
                 if (s->bit_depth == 8 &&
                     s->color_type == PNG_COLOR_TYPE_RGB) {
-                    avctx->pix_fmt = PIX_FMT_RGB24;
+                    avctx->pix_fmt = AV_PIX_FMT_RGB24;
                 } else if (s->bit_depth == 8 &&
                            s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
-                    avctx->pix_fmt = PIX_FMT_RGB32;
+                    avctx->pix_fmt = AV_PIX_FMT_RGB32;
                 } else if (s->bit_depth == 8 &&
                            s->color_type == PNG_COLOR_TYPE_GRAY) {
-                    avctx->pix_fmt = PIX_FMT_GRAY8;
+                    avctx->pix_fmt = AV_PIX_FMT_GRAY8;
                 } else if (s->bit_depth == 16 &&
                            s->color_type == PNG_COLOR_TYPE_GRAY) {
-                    avctx->pix_fmt = PIX_FMT_GRAY16BE;
+                    avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
                 } else if (s->bit_depth == 16 &&
                            s->color_type == PNG_COLOR_TYPE_RGB) {
-                    avctx->pix_fmt = PIX_FMT_RGB48BE;
+                    avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
                 } else if (s->bit_depth == 1 &&
                            s->color_type == PNG_COLOR_TYPE_GRAY) {
-                    avctx->pix_fmt = PIX_FMT_MONOBLACK;
-                } else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
-                    avctx->pix_fmt = PIX_FMT_PAL8;
-                } else if (s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
-                    avctx->pix_fmt = PIX_FMT_Y400A;
+                    avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
+                } else if (s->bit_depth == 8 &&
+                           s->color_type == PNG_COLOR_TYPE_PALETTE) {
+                    avctx->pix_fmt = AV_PIX_FMT_PAL8;
+                } else if (s->bit_depth == 8 &&
+                           s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
+                    avctx->pix_fmt = AV_PIX_FMT_Y400A;
                 } else {
                     goto fail;
                 }
-                if(p->data[0])
+                if (p->data[0])
                     avctx->release_buffer(avctx, p);
 
-                p->reference= 0;
-                if(avctx->get_buffer(avctx, p) < 0){
+                p->reference = 0;
+                if (ff_get_buffer(avctx, p) < 0) {
                     av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
                     goto fail;
                 }
-                p->pict_type= FF_I_TYPE;
-                p->key_frame= 1;
+                p->pict_type        = AV_PICTURE_TYPE_I;
+                p->key_frame        = 1;
                 p->interlaced_frame = !!s->interlace_type;
 
                 /* compute the compressed row size */
@@ -516,9 +514,9 @@ static int decode_frame(AVCodecContext *avctx,
                                                          s->width);
                     s->crow_size = s->pass_row_size + 1;
                 }
-                dprintf(avctx, "row_size=%d crow_size =%d\n",
+                av_dlog(avctx, "row_size=%d crow_size =%d\n",
                         s->row_size, s->crow_size);
-                s->image_buf = p->data[0];
+                s->image_buf      = p->data[0];
                 s->image_linesize = p->linesize[0];
                 /* copy the palette if needed */
                 if (s->color_type == PNG_COLOR_TYPE_PALETTE)
@@ -539,15 +537,14 @@ static int decode_frame(AVCodecContext *avctx,
                     goto fail;
 
                 /* we want crow_buf+1 to be 16-byte aligned */
-                s->crow_buf = crow_buf_base + 15;
+                s->crow_buf          = crow_buf_base + 15;
                 s->zstream.avail_out = s->crow_size;
-                s->zstream.next_out = s->crow_buf;
+                s->zstream.next_out  = s->crow_buf;
             }
             s->state |= PNG_IDAT;
             if (png_decode_idat(s, length) < 0)
                 goto fail;
-            /* skip crc */
-            crc = bytestream_get_be32(&s->bytestream);
+            bytestream2_skip(&s->gb, 4); /* crc */
             break;
         case MKTAG('P', 'L', 'T', 'E'):
             {
@@ -557,17 +554,17 @@ static int decode_frame(AVCodecContext *avctx,
                     goto skip_tag;
                 /* read the palette */
                 n = length / 3;
-                for(i=0;i<n;i++) {
-                    r = *s->bytestream++;
-                    g = *s->bytestream++;
-                    b = *s->bytestream++;
+                for (i = 0; i < n; i++) {
+                    r = bytestream2_get_byte(&s->gb);
+                    g = bytestream2_get_byte(&s->gb);
+                    b = bytestream2_get_byte(&s->gb);
                     s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b;
                 }
-                for(;i<256;i++) {
+                for (; i < 256; i++) {
                     s->palette[i] = (0xff << 24);
                 }
                 s->state |= PNG_PLTE;
-                crc = bytestream_get_be32(&s->bytestream);
+                bytestream2_skip(&s->gb, 4); /* crc */
             }
             break;
         case MKTAG('t', 'R', 'N', 'S'):
@@ -579,47 +576,47 @@ static int decode_frame(AVCodecContext *avctx,
                     length > 256 ||
                     !(s->state & PNG_PLTE))
                     goto skip_tag;
-                for(i=0;i<length;i++) {
-                    v = *s->bytestream++;
+                for (i = 0; i < length; i++) {
+                    v = bytestream2_get_byte(&s->gb);
                     s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
                 }
-                crc = bytestream_get_be32(&s->bytestream);
+                bytestream2_skip(&s->gb, 4); /* crc */
             }
             break;
         case MKTAG('I', 'E', 'N', 'D'):
             if (!(s->state & PNG_ALLIMAGE))
                 goto fail;
-            crc = bytestream_get_be32(&s->bytestream);
+            bytestream2_skip(&s->gb, 4); /* crc */
             goto exit_loop;
         default:
             /* skip tag */
         skip_tag:
-            s->bytestream += length + 4;
+            bytestream2_skip(&s->gb, length + 4);
             break;
         }
     }
  exit_loop:
      /* handle p-frames only if a predecessor frame is available */
-     if(s->last_picture->data[0] != NULL) {
-         if(!(avpkt->flags & AV_PKT_FLAG_KEY)) {
+     if (s->last_picture->data[0] != NULL) {
+         if (!(avpkt->flags & AV_PKT_FLAG_KEY)) {
             int i, j;
-            uint8_t *pd = s->current_picture->data[0];
+            uint8_t *pd      = s->current_picture->data[0];
             uint8_t *pd_last = s->last_picture->data[0];
 
-            for(j=0; j < s->height; j++) {
-                for(i=0; i < s->width * s->bpp; i++) {
+            for (j = 0; j < s->height; j++) {
+                for (i = 0; i < s->width * s->bpp; i++) {
                     pd[i] += pd_last[i];
                 }
-                pd += s->image_linesize;
+                pd      += s->image_linesize;
                 pd_last += s->image_linesize;
             }
         }
     }
 
-    *picture= *s->current_picture;
-    *data_size = sizeof(AVFrame);
+    *picture   = *s->current_picture;
+    *got_frame = 1;
 
-    ret = s->bytestream - s->bytestream_start;
+    ret = bytestream2_tell(&s->gb);
  the_end:
     inflateEnd(&s->zstream);
     av_free(crow_buf_base);
@@ -632,14 +629,15 @@ static int decode_frame(AVCodecContext *avctx,
     goto the_end;
 }
 
-static av_cold int png_dec_init(AVCodecContext *avctx){
+static av_cold int png_dec_init(AVCodecContext *avctx)
+{
     PNGDecContext *s = avctx->priv_data;
 
     s->current_picture = &s->picture1;
-    s->last_picture = &s->picture2;
+    s->last_picture    = &s->picture2;
     avcodec_get_frame_defaults(&s->picture1);
     avcodec_get_frame_defaults(&s->picture2);
-    dsputil_init(&s->dsp, avctx);
+    ff_pngdsp_init(&s->dsp);
 
     return 0;
 }
@@ -656,17 +654,14 @@ static av_cold int png_dec_end(AVCodecContext *avctx)
     return 0;
 }
 
-AVCodec png_decoder = {
-    "png",
-    AVMEDIA_TYPE_VIDEO,
-    CODEC_ID_PNG,
-    sizeof(PNGDecContext),
-    png_dec_init,
-    NULL,
-    png_dec_end,
-    decode_frame,
-    CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
-    NULL,
-    .max_lowres = 5,
-    .long_name = NULL_IF_CONFIG_SMALL("PNG image"),
+AVCodec ff_png_decoder = {
+    .name           = "png",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_PNG,
+    .priv_data_size = sizeof(PNGDecContext),
+    .init           = png_dec_init,
+    .close          = png_dec_end,
+    .decode         = decode_frame,
+    .capabilities   = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
+    .long_name      = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
 };