[FFmpeg-devel] [PATCH 2/2] avcodec: add WinCAM Motion Video decoder
Rostislav Pehlivanov
atomnuker at gmail.com
Mon Aug 27 21:31:21 EEST 2018
On Sat, 25 Aug 2018 at 21:12, Paul B Mahol <onemda at gmail.com> wrote:
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
> configure | 1 +
> libavcodec/Makefile | 1 +
> libavcodec/allcodecs.c | 1 +
> libavcodec/avcodec.h | 1 +
> libavcodec/codec_desc.c | 7 ++
> libavcodec/wcmv.c | 247 ++++++++++++++++++++++++++++++++++++++++
> libavformat/riff.c | 1 +
> 7 files changed, 259 insertions(+)
> create mode 100644 libavcodec/wcmv.c
>
> diff --git a/configure b/configure
> index 0c1f6a79a7..469797935e 100755
> --- a/configure
> +++ b/configure
> @@ -2750,6 +2750,7 @@ vp6f_decoder_select="vp6_decoder"
> vp7_decoder_select="h264pred videodsp vp8dsp"
> vp8_decoder_select="h264pred videodsp vp8dsp"
> vp9_decoder_select="videodsp vp9_parser vp9_superframe_split_bsf"
> +wcmv_decoder_deps="zlib"
> webp_decoder_select="vp8_decoder exif"
> wmalossless_decoder_select="llauddsp"
> wmapro_decoder_select="mdct sinewin wma_freqs"
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index aee4f5431a..f8673f0121 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -677,6 +677,7 @@ OBJS-$(CONFIG_VP9_V4L2M2M_DECODER) +=
> v4l2_m2m_dec.o
> OBJS-$(CONFIG_VQA_DECODER) += vqavideo.o
> OBJS-$(CONFIG_WAVPACK_DECODER) += wavpack.o
> OBJS-$(CONFIG_WAVPACK_ENCODER) += wavpackenc.o
> +OBJS-$(CONFIG_WCMV_DECODER) += wcmv.o
> OBJS-$(CONFIG_WEBP_DECODER) += webp.o
> OBJS-$(CONFIG_WEBVTT_DECODER) += webvttdec.o ass.o
> OBJS-$(CONFIG_WEBVTT_ENCODER) += webvttenc.o ass_split.o
> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
> index d41868c591..42d98f9b0a 100644
> --- a/libavcodec/allcodecs.c
> +++ b/libavcodec/allcodecs.c
> @@ -338,6 +338,7 @@ extern AVCodec ff_vp9_v4l2m2m_decoder;
> extern AVCodec ff_vqa_decoder;
> extern AVCodec ff_bitpacked_decoder;
> extern AVCodec ff_webp_decoder;
> +extern AVCodec ff_wcmv_decoder;
> extern AVCodec ff_wrapped_avframe_encoder;
> extern AVCodec ff_wrapped_avframe_decoder;
> extern AVCodec ff_wmv1_encoder;
> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> index be41b8cf0e..b6688b7af3 100644
> --- a/libavcodec/avcodec.h
> +++ b/libavcodec/avcodec.h
> @@ -450,6 +450,7 @@ enum AVCodecID {
> AV_CODEC_ID_IMM4,
> AV_CODEC_ID_PROSUMER,
> AV_CODEC_ID_MWSC,
> + AV_CODEC_ID_WCMV,
>
> /* 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 129d0f1aac..46dfe3f5e5 100644
> --- a/libavcodec/codec_desc.c
> +++ b/libavcodec/codec_desc.c
> @@ -1675,6 +1675,13 @@ static const AVCodecDescriptor codec_descriptors[]
> = {
> .long_name = NULL_IF_CONFIG_SMALL("MatchWare Screen Capture
> Codec"),
> .props = AV_CODEC_PROP_LOSSLESS,
> },
> + {
> + .id = AV_CODEC_ID_WCMV,
> + .type = AVMEDIA_TYPE_VIDEO,
> + .name = "wcmv",
> + .long_name = NULL_IF_CONFIG_SMALL("WinCAM Motion Video"),
> + .props = AV_CODEC_PROP_LOSSLESS,
> + },
>
> /* various PCM "codecs" */
> {
> diff --git a/libavcodec/wcmv.c b/libavcodec/wcmv.c
> new file mode 100644
> index 0000000000..74cb1166bb
> --- /dev/null
> +++ b/libavcodec/wcmv.c
> @@ -0,0 +1,247 @@
> +/*
> + * WinCAM Motion Video decoder
> + *
> + * Copyright (c) 2018 Paul B Mahol
> + *
> + * 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 <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +
> +#include "avcodec.h"
> +#include "bytestream.h"
> +#include "internal.h"
> +
> +#include <zlib.h>
> +
> +typedef struct WCMVContext {
> + z_stream zstream;
> + AVFrame *prev_frame;
> + uint8_t block_data[65536*8];
> +} WCMVContext;
> +
> +static int decode_frame(AVCodecContext *avctx,
> + void *data, int *got_frame,
> + AVPacket *avpkt)
> +{
> + WCMVContext *s = avctx->priv_data;
> + AVFrame *frame = data;
> + int skip, blocks, zret, ret, intra = 0;
> + GetByteContext gb;
> + uint8_t *dst;
> +
> + ret = inflateReset(&s->zstream);
> + if (ret != Z_OK) {
> + av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
> + return AVERROR_EXTERNAL;
> + }
> +
> + bytestream2_init(&gb, avpkt->data, avpkt->size);
> +
> + if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
> + return ret;
> +
> + if (s->prev_frame->data[0]) {
> + ret = av_frame_copy(frame, s->prev_frame);
> + if (ret < 0)
> + return ret;
> + }
>
Shouldn't it be zero'd out if case there's no prev_frame?
> +
> + blocks = bytestream2_get_le16(&gb);
> + if (blocks > 5) {
> + GetByteContext bgb;
> + int x = 0, size;
> +
> + if (blocks * 8 >= 0xFFFF) {
> + size = bytestream2_get_le24(&gb);
> + } else if (blocks * 8 >= 0xFF) {
> + size = bytestream2_get_le16(&gb);
> + } else {
> + size = bytestream2_get_byte(&gb);
> + }
>
No need for brackets here, they're all one line expressions.
+
> + skip = bytestream2_tell(&gb);
> + if (size > avpkt->size - skip)
> + return AVERROR_INVALIDDATA;
> +
> + s->zstream.next_in = avpkt->data + skip;
> + s->zstream.avail_in = size;
> + s->zstream.next_out = s->block_data;
> + s->zstream.avail_out = sizeof(s->block_data);
> +
> + zret = inflate(&s->zstream, Z_FINISH);
> + if (zret != Z_STREAM_END) {
> + av_log(avctx, AV_LOG_ERROR,
> + "Inflate failed with return code: %d.\n", zret);
> + return AVERROR_INVALIDDATA;
> + }
> +
> + ret = inflateReset(&s->zstream);
> + if (ret != Z_OK) {
> + av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
> + return AVERROR_EXTERNAL;
> + }
>
Will zlib error out if the data it tries to unpack is larger than
s->zstream.avail_out = sizeof(s->block_data)?
> +
> + bytestream2_skip(&gb, size);
> + bytestream2_init(&bgb, s->block_data, blocks * 8);
> +
> + for (int i = 0; i < blocks; i++) {
> + int w, h;
> +
> + bytestream2_skip(&bgb, 4);
> + w = bytestream2_get_le16(&bgb);
> + h = bytestream2_get_le16(&bgb);
> + x += 3 * w * h;
> + }
> +
> + if (x >= 0xFFFF) {
> + bytestream2_skip(&gb, 3);
> + } else if (x >= 0xFF) {
> + bytestream2_skip(&gb, 2);
> + } else {
> + bytestream2_skip(&gb, 1);
> + }
>
Same, oneliners so no need for brackets.
+
> + skip = bytestream2_tell(&gb);
> +
> + s->zstream.next_in = avpkt->data + skip;
> + s->zstream.avail_in = avpkt->size - skip;
> +
> + bytestream2_init(&gb, s->block_data, blocks * 8);
> + } else {
> + int x = 0;
> +
> + bytestream2_seek(&gb, 2, SEEK_SET);
> +
> + for (int i = 0; i < blocks; i++) {
> + int w, h;
> +
> + bytestream2_skip(&gb, 4);
> + w = bytestream2_get_le16(&gb);
> + h = bytestream2_get_le16(&gb);
> + x += 3 * w * h;
> + }
> +
> + if (x >= 0xFFFF) {
> + bytestream2_skip(&gb, 3);
> + } else if (x >= 0xFF) {
> + bytestream2_skip(&gb, 2);
> + } else {
> + bytestream2_skip(&gb, 1);
> + }
>
Same.
> +
> + skip = bytestream2_tell(&gb);
> +
> + s->zstream.next_in = avpkt->data + skip;
> + s->zstream.avail_in = avpkt->size - skip;
> +
> + bytestream2_seek(&gb, 2, SEEK_SET);
> + }
> +
> + for (int block = 0; block < blocks; block++) {
> + int x, y, w, h;
> +
> + x = bytestream2_get_le16(&gb);
> + y = bytestream2_get_le16(&gb);
> + w = bytestream2_get_le16(&gb);
> + h = bytestream2_get_le16(&gb);
> +
> + if (blocks == 1 && x == 0 && y == 0 && w == avctx->width && h ==
> avctx->height)
> + intra = 1;
> +
> + if (x + w > avctx->width || y + h > avctx->height)
> + return AVERROR_INVALIDDATA;
> +
> + if (w > avctx->width || h > avctx->height)
> + return AVERROR_INVALIDDATA;
> +
> + dst = frame->data[0] + (avctx->height - y - 1) *
> frame->linesize[0] + x * 3;
> + for (int i = 0; i < h; i++) {
> + s->zstream.next_out = dst;
> + s->zstream.avail_out = w * 3;
> +
> + zret = inflate(&s->zstream, Z_SYNC_FLUSH);
> + if (zret != Z_OK && zret != Z_STREAM_END) {
> + av_log(avctx, AV_LOG_ERROR,
> + "Inflate failed with return code: %d.\n", zret);
> + return AVERROR_INVALIDDATA;
> + }
> +
> + dst -= frame->linesize[0];
> + }
> + }
> +
> + frame->key_frame = intra;
> + frame->pict_type = intra ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
> +
> + av_frame_unref(s->prev_frame);
> + if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
> + return ret;
> +
> + *got_frame = 1;
> +
> + return avpkt->size;
> +}
> +
> +static av_cold int decode_init(AVCodecContext *avctx)
> +{
> + WCMVContext *s = avctx->priv_data;
> + int zret;
> +
> + avctx->pix_fmt = AV_PIX_FMT_BGR24;
> +
> + s->zstream.zalloc = Z_NULL;
> + s->zstream.zfree = Z_NULL;
> + s->zstream.opaque = Z_NULL;
> + zret = inflateInit(&s->zstream);
> + if (zret != Z_OK) {
> + av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
> + return AVERROR_EXTERNAL;
> + }
> +
> + s->prev_frame = av_frame_alloc();
> + if (!s->prev_frame)
> + return AVERROR(ENOMEM);
> +
> + return 0;
> +}
> +
> +static av_cold int decode_close(AVCodecContext *avctx)
> +{
> + WCMVContext *s = avctx->priv_data;
> +
> + av_frame_free(&s->prev_frame);
> + inflateEnd(&s->zstream);
> +
> + return 0;
> +}
> +
> +AVCodec ff_wcmv_decoder = {
> + .name = "wcmv",
> + .long_name = NULL_IF_CONFIG_SMALL("WinCAM Motion Video"),
> + .type = AVMEDIA_TYPE_VIDEO,
> + .id = AV_CODEC_ID_WCMV,
> + .priv_data_size = sizeof(WCMVContext),
> + .init = decode_init,
> + .close = decode_close,
> + .decode = decode_frame,
> + .capabilities = AV_CODEC_CAP_DR1,
> + .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
> + FF_CODEC_CAP_INIT_CLEANUP,
> +};
> diff --git a/libavformat/riff.c b/libavformat/riff.c
> index aef3c047ac..5f1aafe514 100644
> --- a/libavformat/riff.c
> +++ b/libavformat/riff.c
> @@ -473,6 +473,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
> { AV_CODEC_ID_IMM4, MKTAG('I', 'M', 'M', '4') },
> { AV_CODEC_ID_PROSUMER, MKTAG('B', 'T', '2', '0') },
> { AV_CODEC_ID_MWSC, MKTAG('M', 'W', 'S', 'C') },
> + { AV_CODEC_ID_WCMV, MKTAG('W', 'C', 'M', 'V') },
> { AV_CODEC_ID_NONE, 0 }
> };
>
> --
> 2.17.1
>
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lavc micro bump + line in changelog.
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