avcodec/pngdec: create a function to decode IDAT chunk.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 109 insertions, 98 deletions

diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 99a3a72389..8199bd8236 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -563,6 +563,114 @@ static int decode_phys_chunk(AVCodecContext *avctx, PNGDecContext *s)
     return 0;
 }
 
+static int decode_idat_chunk(AVCodecContext *avctx, PNGDecContext *s,
+                             uint32_t length, AVFrame *p)
+{
+    int ret;
+
+    if (!(s->state & PNG_IHDR)) {
+        av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
+        return AVERROR_INVALIDDATA;
+    }
+    if (!(s->state & PNG_IDAT)) {
+        /* init image info */
+        avctx->width  = s->width;
+        avctx->height = s->height;
+
+        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;
+
+        if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
+                s->color_type == PNG_COLOR_TYPE_RGB) {
+            avctx->pix_fmt = AV_PIX_FMT_RGB24;
+        } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
+                s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
+            avctx->pix_fmt = AV_PIX_FMT_RGBA;
+        } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
+                s->color_type == PNG_COLOR_TYPE_GRAY) {
+            avctx->pix_fmt = AV_PIX_FMT_GRAY8;
+        } else if (s->bit_depth == 16 &&
+                s->color_type == PNG_COLOR_TYPE_GRAY) {
+            avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
+        } else if (s->bit_depth == 16 &&
+                s->color_type == PNG_COLOR_TYPE_RGB) {
+            avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
+        } else if (s->bit_depth == 16 &&
+                s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
+            avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
+        } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
+                s->color_type == PNG_COLOR_TYPE_PALETTE) {
+            avctx->pix_fmt = AV_PIX_FMT_PAL8;
+        } else if (s->bit_depth == 1 && s->bits_per_pixel == 1) {
+            avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
+        } else if (s->bit_depth == 8 &&
+                s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
+            avctx->pix_fmt = AV_PIX_FMT_YA8;
+        } else if (s->bit_depth == 16 &&
+                s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
+            avctx->pix_fmt = AV_PIX_FMT_YA16BE;
+        } else {
+            av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d "
+                    "and color type %d\n",
+                    s->bit_depth, s->color_type);
+            return AVERROR_INVALIDDATA;
+        }
+
+        if ((ret = ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF)) < 0)
+            return ret;
+        ff_thread_finish_setup(avctx);
+
+        p->pict_type        = AV_PICTURE_TYPE_I;
+        p->key_frame        = 1;
+        p->interlaced_frame = !!s->interlace_type;
+
+        /* compute the compressed row size */
+        if (!s->interlace_type) {
+            s->crow_size = s->row_size + 1;
+        } else {
+            s->pass          = 0;
+            s->pass_row_size = ff_png_pass_row_size(s->pass,
+                    s->bits_per_pixel,
+                    s->width);
+            s->crow_size = s->pass_row_size + 1;
+        }
+        av_dlog(avctx, "row_size=%d crow_size =%d\n",
+                s->row_size, s->crow_size);
+        s->image_buf      = p->data[0];
+        s->image_linesize = p->linesize[0];
+        /* copy the palette if needed */
+        if (avctx->pix_fmt == AV_PIX_FMT_PAL8)
+            memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
+        /* empty row is used if differencing to the first row */
+        av_fast_padded_mallocz(&s->last_row, &s->last_row_size, s->row_size);
+        if (!s->last_row)
+            return AVERROR_INVALIDDATA;
+        if (s->interlace_type ||
+                s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
+            av_fast_padded_malloc(&s->tmp_row, &s->tmp_row_size, s->row_size);
+            if (!s->tmp_row)
+                return AVERROR_INVALIDDATA;
+        }
+        /* compressed row */
+        av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16);
+        if (!s->buffer)
+            return AVERROR(ENOMEM);
+
+        /* we want crow_buf+1 to be 16-byte aligned */
+        s->crow_buf          = s->buffer + 15;
+        s->zstream.avail_out = s->crow_size;
+        s->zstream.next_out  = s->crow_buf;
+    }
+    s->state |= PNG_IDAT;
+    if ((ret = png_decode_idat(s, length)) < 0)
+        return ret;
+    bytestream2_skip(&s->gb, 4); /* crc */
+
+    return 0;
+}
+
 static int decode_frame_png(AVCodecContext *avctx,
                         void *data, int *got_frame,
                         AVPacket *avpkt)
@@ -632,105 +740,8 @@ static int decode_frame_png(AVCodecContext *avctx,
                 goto fail;
             break;
         case MKTAG('I', 'D', 'A', 'T'):
-            if (!(s->state & PNG_IHDR)) {
-                av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
-                goto fail;
-            }
-            if (!(s->state & PNG_IDAT)) {
-                /* init image info */
-                avctx->width  = s->width;
-                avctx->height = s->height;
-
-                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;
-
-                if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
-                    s->color_type == PNG_COLOR_TYPE_RGB) {
-                    avctx->pix_fmt = AV_PIX_FMT_RGB24;
-                } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
-                           s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
-                    avctx->pix_fmt = AV_PIX_FMT_RGBA;
-                } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
-                           s->color_type == PNG_COLOR_TYPE_GRAY) {
-                    avctx->pix_fmt = AV_PIX_FMT_GRAY8;
-                } else if (s->bit_depth == 16 &&
-                           s->color_type == PNG_COLOR_TYPE_GRAY) {
-                    avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
-                } else if (s->bit_depth == 16 &&
-                           s->color_type == PNG_COLOR_TYPE_RGB) {
-                    avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
-                } else if (s->bit_depth == 16 &&
-                           s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
-                    avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
-                } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
-                           s->color_type == PNG_COLOR_TYPE_PALETTE) {
-                    avctx->pix_fmt = AV_PIX_FMT_PAL8;
-                } else if (s->bit_depth == 1 && s->bits_per_pixel == 1) {
-                    avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
-                } else if (s->bit_depth == 8 &&
-                           s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
-                    avctx->pix_fmt = AV_PIX_FMT_YA8;
-                } else if (s->bit_depth == 16 &&
-                           s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
-                    avctx->pix_fmt = AV_PIX_FMT_YA16BE;
-                } else {
-                    av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d "
-                                                "and color type %d\n",
-                                                 s->bit_depth, s->color_type);
-                    goto fail;
-                }
-
-                if (ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF) < 0)
-                    goto fail;
-                ff_thread_finish_setup(avctx);
-
-                p->pict_type        = AV_PICTURE_TYPE_I;
-                p->key_frame        = 1;
-                p->interlaced_frame = !!s->interlace_type;
-
-                /* compute the compressed row size */
-                if (!s->interlace_type) {
-                    s->crow_size = s->row_size + 1;
-                } else {
-                    s->pass          = 0;
-                    s->pass_row_size = ff_png_pass_row_size(s->pass,
-                                                            s->bits_per_pixel,
-                                                            s->width);
-                    s->crow_size = s->pass_row_size + 1;
-                }
-                av_dlog(avctx, "row_size=%d crow_size =%d\n",
-                        s->row_size, s->crow_size);
-                s->image_buf      = p->data[0];
-                s->image_linesize = p->linesize[0];
-                /* copy the palette if needed */
-                if (avctx->pix_fmt == AV_PIX_FMT_PAL8)
-                    memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
-                /* empty row is used if differencing to the first row */
-                av_fast_padded_mallocz(&s->last_row, &s->last_row_size, s->row_size);
-                if (!s->last_row)
-                    goto fail;
-                if (s->interlace_type ||
-                    s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
-                    av_fast_padded_malloc(&s->tmp_row, &s->tmp_row_size, s->row_size);
-                    if (!s->tmp_row)
-                        goto fail;
-                }
-                /* compressed row */
-                av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16);
-                if (!s->buffer)
-                    goto fail;
-
-                /* we want crow_buf+1 to be 16-byte aligned */
-                s->crow_buf          = s->buffer + 15;
-                s->zstream.avail_out = s->crow_size;
-                s->zstream.next_out  = s->crow_buf;
-            }
-            s->state |= PNG_IDAT;
-            if (png_decode_idat(s, length) < 0)
+            if (decode_idat_chunk(avctx, s, length, p) < 0)
                 goto fail;
-            bytestream2_skip(&s->gb, 4); /* crc */
             break;
         case MKTAG('P', 'L', 'T', 'E'):
         {