[FFmpeg-devel] avcodec: add LSCR decoder

Submitted by Paul B Mahol on April 12, 2019, 8:12 p.m.

Details

Message ID 20190412201242.5219-1-onemda@gmail.com
State New
Headers show

Commit Message

Paul B Mahol April 12, 2019, 8:12 p.m.
Signed-off-by: Paul B Mahol <onemda@gmail.com>
---
 libavcodec/Makefile     |   1 +
 libavcodec/allcodecs.c  |   1 +
 libavcodec/avcodec.h    |   1 +
 libavcodec/codec_desc.c |   7 +++
 libavcodec/pngdec.c     | 135 ++++++++++++++++++++++++++++++++++++++++
 libavformat/riff.c      |   1 +
 6 files changed, 146 insertions(+)

Comments

Paul B Mahol April 13, 2019, 3:07 p.m.
On 4/12/19, Paul B Mahol <onemda@gmail.com> wrote:
> Signed-off-by: Paul B Mahol <onemda@gmail.com>
> ---
>  libavcodec/Makefile     |   1 +
>  libavcodec/allcodecs.c  |   1 +
>  libavcodec/avcodec.h    |   1 +
>  libavcodec/codec_desc.c |   7 +++
>  libavcodec/pngdec.c     | 135 ++++++++++++++++++++++++++++++++++++++++
>  libavformat/riff.c      |   1 +
>  6 files changed, 146 insertions(+)
>

Will push improved patch soon.

Patch hide | download patch | download mbox

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 2e35681867..f37135fc07 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -413,6 +413,7 @@  OBJS-$(CONFIG_KMVC_DECODER)            += kmvc.o
 OBJS-$(CONFIG_LAGARITH_DECODER)        += lagarith.o lagarithrac.o
 OBJS-$(CONFIG_LJPEG_ENCODER)           += ljpegenc.o mjpegenc_common.o
 OBJS-$(CONFIG_LOCO_DECODER)            += loco.o
+OBJS-$(CONFIG_LSCR_DECODER)            += png.o pngdec.o pngdsp.o
 OBJS-$(CONFIG_M101_DECODER)            += m101.o
 OBJS-$(CONFIG_MACE3_DECODER)           += mace.o
 OBJS-$(CONFIG_MACE6_DECODER)           += mace.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 9ae8a779b3..6178d31b5c 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -173,6 +173,7 @@  extern AVCodec ff_kmvc_decoder;
 extern AVCodec ff_lagarith_decoder;
 extern AVCodec ff_ljpeg_encoder;
 extern AVCodec ff_loco_decoder;
+extern AVCodec ff_lscr_decoder;
 extern AVCodec ff_m101_decoder;
 extern AVCodec ff_magicyuv_encoder;
 extern AVCodec ff_magicyuv_decoder;
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 4218cff6c4..9e37466641 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -455,6 +455,7 @@  enum AVCodecID {
     AV_CODEC_ID_HYMT,
     AV_CODEC_ID_ARBC,
     AV_CODEC_ID_AGM,
+    AV_CODEC_ID_LSCR,
 
     /* various PCM "codecs" */
     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 8295221d15..621b16e160 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1712,6 +1712,13 @@  static const AVCodecDescriptor codec_descriptors[] = {
         .long_name = NULL_IF_CONFIG_SMALL("Amuse Graphics Movie"),
         .props     = AV_CODEC_PROP_LOSSY,
     },
+    {
+        .id        = AV_CODEC_ID_LSCR,
+        .type      = AVMEDIA_TYPE_VIDEO,
+        .name      = "lscr",
+        .long_name = NULL_IF_CONFIG_SMALL("LEAD Screen Capture"),
+        .props     = AV_CODEC_PROP_LOSSY,
+    },
 
     /* various PCM "codecs" */
     {
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 189bb9a4c1..c55340a28e 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -1525,6 +1525,123 @@  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++) {
+        uint16_t x, y, x2, y2, w, h;
+        uint32_t csize, size;
+        int left;
+
+        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;
+        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)
+            return AVERROR(ENOMEM);
+
+        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;
+
+        av_fast_padded_malloc(&s->last_row, &s->last_row_size, s->row_size);
+        if (!s->last_row)
+            return AVERROR_INVALIDDATA;
+
+        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;
+}
+#endif
+
 #if HAVE_THREADS
 static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
 {
@@ -1581,6 +1698,9 @@  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 +1773,18 @@  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,
+    .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
diff --git a/libavformat/riff.c b/libavformat/riff.c
index 741a6515df..0f5cd62547 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -485,6 +485,7 @@  const AVCodecTag ff_codec_bmp_tags[] = {
     { AV_CODEC_ID_AGM,          MKTAG('A', 'G', 'M', '5') },
     { AV_CODEC_ID_AGM,          MKTAG('A', 'G', 'M', '6') },
     { AV_CODEC_ID_AGM,          MKTAG('A', 'G', 'M', '7') },
+    { AV_CODEC_ID_LSCR,         MKTAG('L', 'S', 'C', 'R') },
     { AV_CODEC_ID_NONE,         0 }
 };