[FFmpeg-devel] [PATCH 2/6] lavc: split LSCR decoder out of PNG decoder
Paul B Mahol
onemda at gmail.com
Tue Feb 16 22:33:32 EET 2021
I do not like this.
On Tue, Feb 16, 2021 at 9:26 PM Anton Khirnov <anton at khirnov.net> wrote:
> It shares very little code with pngdec, so keeping them together only
> makes the code harder to read.
> ---
> libavcodec/Makefile | 2 +-
> libavcodec/lscrdec.c | 279 +++++++++++++++++++++++++++++++++++++++++++
> libavcodec/png.h | 5 +
> libavcodec/pngdec.c | 174 +--------------------------
> 4 files changed, 291 insertions(+), 169 deletions(-)
> create mode 100644 libavcodec/lscrdec.c
>
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 3341801b97..b0c6d675d0 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..242ae8fcb2
> --- /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, AVFrame *frame)
> +{
> + 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, AVFrame *frame, 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, frame);
> + }
> + 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, frame, 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
> --
> 2.28.0
>
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