X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fpngdec.c;h=6a681be29d795a01157a3cc1bf6a9afa68393468;hb=81acc9adbfef9a4867862033b769b5d198cea679;hp=189bb9a4c1733d25a7baae6c43c254dbfac52b89;hpb=29929fc8e2449d2db8bd144b2badc8d1e6347412;p=ffmpeg

diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 189bb9a4c17..6a681be29d7 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -1525,6 +1525,141 @@ end:
 }
 #endif
 
+#if CONFIG_LSCR_DECODER
+static int decode_frame_lscr(AVCodecContext *avctx,
+                             void *data, int *got_frame,
+                             AVPacket *avpkt)
+{
+    PNGDecContext *const s = avctx->priv_data;
+    GetByteContext *gb = &s->gb;
+    AVFrame *frame = data;
+    int ret, nb_blocks, offset = 0;
+
+    bytestream2_init(gb, avpkt->data, avpkt->size);
+
+    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
+        return ret;
+
+    nb_blocks = bytestream2_get_le16(gb);
+
+    if (s->last_picture.f->data[0]) {
+        ret = av_frame_copy(frame, s->last_picture.f);
+        if (ret < 0)
+            return ret;
+    }
+
+    for (int b = 0; b < nb_blocks; b++) {
+        int x, y, x2, y2, w, h, left;
+        uint32_t csize, size;
+
+        s->zstream.zalloc = ff_png_zalloc;
+        s->zstream.zfree  = ff_png_zfree;
+        s->zstream.opaque = NULL;
+
+        if ((ret = inflateInit(&s->zstream)) != Z_OK) {
+            av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
+            ret = AVERROR_EXTERNAL;
+            goto end;
+        }
+
+        bytestream2_seek(gb, 2 + b * 12, SEEK_SET);
+
+        x = bytestream2_get_le16(gb);
+        y = bytestream2_get_le16(gb);
+        x2 = bytestream2_get_le16(gb);
+        y2 = bytestream2_get_le16(gb);
+        s->width  = s->cur_w = w = x2-x;
+        s->height = s->cur_h = h = y2-y;
+
+        if (w <= 0 || x < 0 || x >= avctx->width || w + x > avctx->width ||
+            h <= 0 || y < 0 || y >= avctx->height || h + y > avctx->height) {
+            ret = AVERROR_INVALIDDATA;
+            goto end;
+        }
+
+        size = bytestream2_get_le32(gb);
+
+        frame->key_frame = (nb_blocks == 1) &&
+                           (w == avctx->width) &&
+                           (h == avctx->height) &&
+                           (x == 0) && (y == 0);
+
+        bytestream2_seek(gb, 2 + nb_blocks * 12 + offset, SEEK_SET);
+        csize = bytestream2_get_be32(gb);
+        if (bytestream2_get_le32(gb) != MKTAG('I', 'D', 'A', 'T')) {
+            ret = AVERROR_INVALIDDATA;
+            goto end;
+        }
+
+        offset += size;
+        left = size;
+
+        s->y                 = 0;
+        s->row_size          = w * 3;
+
+        av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16);
+        if (!s->buffer) {
+            ret = AVERROR(ENOMEM);
+            goto end;
+        }
+
+        av_fast_padded_malloc(&s->last_row, &s->last_row_size, s->row_size);
+        if (!s->last_row) {
+            ret = AVERROR(ENOMEM);
+            goto end;
+        }
+
+        s->crow_size         = w * 3 + 1;
+        s->crow_buf          = s->buffer + 15;
+        s->zstream.avail_out = s->crow_size;
+        s->zstream.next_out  = s->crow_buf;
+        s->image_buf         = frame->data[0] + (avctx->height - y - 1) * frame->linesize[0] + x * 3;
+        s->image_linesize    =-frame->linesize[0];
+        s->bpp               = 3;
+        s->pic_state         = 0;
+
+        while (left > 16) {
+            ret = png_decode_idat(s, csize);
+            if (ret < 0)
+                goto end;
+            left -= csize + 16;
+            if (left > 16) {
+                bytestream2_skip(gb, 4);
+                csize = bytestream2_get_be32(gb);
+                if (bytestream2_get_le32(gb) != MKTAG('I', 'D', 'A', 'T')) {
+                    ret = AVERROR_INVALIDDATA;
+                    goto end;
+                }
+            }
+        }
+
+        inflateEnd(&s->zstream);
+    }
+
+    frame->pict_type = frame->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
+
+    av_frame_unref(s->last_picture.f);
+    if ((ret = av_frame_ref(s->last_picture.f, frame)) < 0)
+        return ret;
+
+    *got_frame = 1;
+end:
+    inflateEnd(&s->zstream);
+
+    if (ret < 0)
+        return ret;
+    return avpkt->size;
+}
+
+static void decode_flush(AVCodecContext *avctx)
+{
+    PNGDecContext *s = avctx->priv_data;
+
+    av_frame_unref(s->last_picture.f);
+}
+
+#endif
+
 #if HAVE_THREADS
 static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
 {
@@ -1581,6 +1716,9 @@ static av_cold int png_dec_init(AVCodecContext *avctx)
 
     avctx->color_range = AVCOL_RANGE_JPEG;
 
+    if (avctx->codec_id == AV_CODEC_ID_LSCR)
+        avctx->pix_fmt = AV_PIX_FMT_BGR24;
+
     s->avctx = avctx;
     s->previous_picture.f = av_frame_alloc();
     s->last_picture.f = av_frame_alloc();
@@ -1653,3 +1791,19 @@ AVCodec ff_png_decoder = {
     .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM | FF_CODEC_CAP_INIT_THREADSAFE,
 };
 #endif
+
+#if CONFIG_LSCR_DECODER
+AVCodec ff_lscr_decoder = {
+    .name           = "lscr",
+    .long_name      = NULL_IF_CONFIG_SMALL("LEAD Screen Capture"),
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_LSCR,
+    .priv_data_size = sizeof(PNGDecContext),
+    .init           = png_dec_init,
+    .close          = png_dec_end,
+    .decode         = decode_frame_lscr,
+    .flush          = decode_flush,
+    .capabilities   = AV_CODEC_CAP_DR1 /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/,
+    .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM | FF_CODEC_CAP_INIT_THREADSAFE,
+};
+#endif