[FFmpeg-cvslog] lavc: split LSCR decoder out of PNG decoder
Anton Khirnov
git at videolan.org
Wed Feb 24 18:18:03 EET 2021
ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Sun Feb 14 15:50:10 2021 +0100| [3a5b857d4c455f20d811cad81c7251af2f82fba2] | committer: Anton Khirnov
lavc: split LSCR decoder out of PNG decoder
It shares very little code with pngdec, so keeping them together only
makes the code harder to read.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3a5b857d4c455f20d811cad81c7251af2f82fba2
---
libavcodec/Makefile | 2 +-
libavcodec/lscrdec.c | 279 +++++++++++++++++++++++++++++++++++++++++++++++++++
libavcodec/png.h | 5 +
libavcodec/pngdec.c | 174 ++------------------------------
4 files changed, 291 insertions(+), 169 deletions(-)
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 6dda8cbb1f..0f67d8d2f6 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -439,7 +439,7 @@ 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_LSCR_DECODER) += lscrdec.o 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/lscrdec.c b/libavcodec/lscrdec.c
new file mode 100644
index 0000000000..5ad0431534
--- /dev/null
+++ b/libavcodec/lscrdec.c
@@ -0,0 +1,279 @@
+/*
+ * 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 <stdint.h>
+#include <zlib.h>
+
+#include "libavutil/frame.h"
+#include "libavutil/error.h"
+#include "libavutil/log.h"
+
+#include "avcodec.h"
+#include "bytestream.h"
+#include "codec.h"
+#include "internal.h"
+#include "packet.h"
+#include "png.h"
+#include "pngdsp.h"
+
+typedef struct LSCRContext {
+ PNGDSPContext dsp;
+ AVCodecContext *avctx;
+
+ AVFrame *last_picture;
+ uint8_t *buffer;
+ int buffer_size;
+ uint8_t *crow_buf;
+ int crow_size;
+ uint8_t *last_row;
+ unsigned int last_row_size;
+
+ GetByteContext gb;
+ uint8_t *image_buf;
+ int image_linesize;
+ int row_size;
+ int cur_h;
+ int y;
+
+ z_stream zstream;
+} LSCRContext;
+
+static void handle_row(LSCRContext *s)
+{
+ uint8_t *ptr, *last_row;
+
+ ptr = s->image_buf + s->image_linesize * s->y;
+ if (s->y == 0)
+ last_row = s->last_row;
+ else
+ last_row = ptr - s->image_linesize;
+
+ ff_png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
+ last_row, s->row_size, 3);
+
+ s->y++;
+}
+
+static int decode_idat(LSCRContext *s, int length)
+{
+ int ret;
+ 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) {
+ ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
+ if (ret != Z_OK && ret != Z_STREAM_END) {
+ av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret);
+ return AVERROR_EXTERNAL;
+ }
+ if (s->zstream.avail_out == 0) {
+ if (s->y < s->cur_h) {
+ handle_row(s);
+ }
+ s->zstream.avail_out = s->crow_size;
+ s->zstream.next_out = s->crow_buf;
+ }
+ if (ret == Z_STREAM_END && s->zstream.avail_in > 0) {
+ av_log(s->avctx, AV_LOG_WARNING,
+ "%d undecompressed bytes left in buffer\n", s->zstream.avail_in);
+ return 0;
+ }
+ }
+ return 0;
+}
+
+static int decode_frame_lscr(AVCodecContext *avctx,
+ void *data, int *got_frame,
+ AVPacket *avpkt)
+{
+ LSCRContext *const s = avctx->priv_data;
+ GetByteContext *gb = &s->gb;
+ AVFrame *frame = data;
+ int ret, nb_blocks, offset = 0;
+
+ if (avpkt->size < 2)
+ return AVERROR_INVALIDDATA;
+ if (avpkt->size == 2)
+ return 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 (bytestream2_get_bytes_left(gb) < 2 + nb_blocks * (12 + 8))
+ return AVERROR_INVALIDDATA;
+
+ if (s->last_picture->data[0]) {
+ ret = av_frame_copy(frame, s->last_picture);
+ 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);
+ w = x2-x;
+ 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];
+
+ while (left > 16) {
+ ret = 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);
+ if ((ret = av_frame_ref(s->last_picture, frame)) < 0)
+ return ret;
+
+ *got_frame = 1;
+end:
+ inflateEnd(&s->zstream);
+
+ if (ret < 0)
+ return ret;
+ return avpkt->size;
+}
+
+static int lscr_decode_close(AVCodecContext *avctx)
+{
+ LSCRContext *s = avctx->priv_data;
+
+ av_frame_free(&s->last_picture);
+ av_freep(&s->buffer);
+ av_freep(&s->last_row);
+
+ return 0;
+}
+
+static int lscr_decode_init(AVCodecContext *avctx)
+{
+ LSCRContext *s = avctx->priv_data;
+
+ avctx->color_range = AVCOL_RANGE_JPEG;
+ avctx->pix_fmt = AV_PIX_FMT_BGR24;
+
+ s->avctx = avctx;
+ s->last_picture = av_frame_alloc();
+ if (!s->last_picture)
+ return AVERROR(ENOMEM);
+
+ ff_pngdsp_init(&s->dsp);
+
+ return 0;
+}
+
+static void lscr_decode_flush(AVCodecContext *avctx)
+{
+ LSCRContext *s = avctx->priv_data;
+ av_frame_unref(s->last_picture);
+}
+
+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(LSCRContext),
+ .init = lscr_decode_init,
+ .close = lscr_decode_close,
+ .decode = decode_frame_lscr,
+ .flush = lscr_decode_flush,
+ .capabilities = AV_CODEC_CAP_DR1,
+ .caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM | FF_CODEC_CAP_INIT_THREADSAFE |
+ FF_CODEC_CAP_ALLOCATE_PROGRESS,
+};
diff --git a/libavcodec/png.h b/libavcodec/png.h
index e967fcf38f..a15560131f 100644
--- a/libavcodec/png.h
+++ b/libavcodec/png.h
@@ -24,6 +24,8 @@
#include <stdint.h>
+#include "pngdsp.h"
+
#define PNG_COLOR_MASK_PALETTE 1
#define PNG_COLOR_MASK_COLOR 2
#define PNG_COLOR_MASK_ALPHA 4
@@ -61,4 +63,7 @@ int ff_png_pass_row_size(int pass, int bits_per_pixel, int width);
void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp);
+void ff_png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
+ uint8_t *src, uint8_t *last, int size, int bpp);
+
#endif /* AVCODEC_PNG_H */
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 61642b7cbe..e05e44f564 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -250,8 +250,8 @@ void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top,
}
/* NOTE: 'dst' can be equal to 'last' */
-static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
- uint8_t *src, uint8_t *last, int size, int bpp)
+void ff_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;
@@ -343,8 +343,8 @@ static void png_handle_row(PNGDecContext *s)
else
last_row = ptr - s->image_linesize;
- png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
- last_row, s->row_size, s->bpp);
+ ff_png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
+ last_row, s->row_size, s->bpp);
/* loco lags by 1 row so that it doesn't interfere with top prediction */
if (s->filter_type == PNG_FILTER_TYPE_LOCO && s->y > 0) {
if (s->bit_depth == 16) {
@@ -377,8 +377,8 @@ static void png_handle_row(PNGDecContext *s)
* wait for the next one */
if (got_line)
break;
- png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
- s->last_row, s->pass_row_size, s->bpp);
+ ff_png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
+ s->last_row, s->pass_row_size, s->bpp);
FFSWAP(uint8_t *, s->last_row, s->tmp_row);
FFSWAP(unsigned int, s->last_row_size, s->tmp_row_size);
got_line = 1;
@@ -1585,148 +1585,6 @@ 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;
-
- if (avpkt->size < 2)
- return AVERROR_INVALIDDATA;
- if (avpkt->size == 2)
- return 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 (bytestream2_get_bytes_left(gb) < 2 + nb_blocks * (12 + 8))
- return AVERROR_INVALIDDATA;
-
- 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)
{
@@ -1783,9 +1641,6 @@ 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();
@@ -1855,20 +1710,3 @@ AVCodec ff_png_decoder = {
FF_CODEC_CAP_ALLOCATE_PROGRESS,
};
#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 |
- FF_CODEC_CAP_ALLOCATE_PROGRESS,
-};
-#endif
More information about the ffmpeg-cvslog
mailing list