[FFmpeg-devel] [PATCH] avcodec: add mvdv video decoder
Paul B Mahol
onemda at gmail.com
Sun Nov 24 11:42:22 EET 2019
On 11/23/19, James Almer <jamrial at gmail.com> wrote:
> On 11/23/2019 5:30 PM, Paul B Mahol wrote:
>> Signed-off-by: Paul B Mahol <onemda at gmail.com>
>> ---
>> libavcodec/Makefile | 1 +
>> libavcodec/allcodecs.c | 1 +
>> libavcodec/avcodec.h | 1 +
>> libavcodec/codec_desc.c | 7 ++
>> libavcodec/midivid.c | 264 ++++++++++++++++++++++++++++++++++++++++
>> libavformat/riff.c | 1 +
>> 6 files changed, 275 insertions(+)
>> create mode 100644 libavcodec/midivid.c
>>
>> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
>> index 006a472a6d..52e5b4f345 100644
>> --- a/libavcodec/Makefile
>> +++ b/libavcodec/Makefile
>> @@ -493,6 +493,7 @@ OBJS-$(CONFIG_MSZH_DECODER) += lcldec.o
>> OBJS-$(CONFIG_MTS2_DECODER) += mss4.o
>> OBJS-$(CONFIG_MVC1_DECODER) += mvcdec.o
>> OBJS-$(CONFIG_MVC2_DECODER) += mvcdec.o
>> +OBJS-$(CONFIG_MVDV_DECODER) += midivid.o
>> OBJS-$(CONFIG_MWSC_DECODER) += mwsc.o
>> OBJS-$(CONFIG_MXPEG_DECODER) += mxpegdec.o
>> OBJS-$(CONFIG_NELLYMOSER_DECODER) += nellymoserdec.o nellymoser.o
>> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
>> index 0c0741936c..4eb1afbea1 100644
>> --- a/libavcodec/allcodecs.c
>> +++ b/libavcodec/allcodecs.c
>> @@ -218,6 +218,7 @@ extern AVCodec ff_mszh_decoder;
>> extern AVCodec ff_mts2_decoder;
>> extern AVCodec ff_mvc1_decoder;
>> extern AVCodec ff_mvc2_decoder;
>> +extern AVCodec ff_mvdv_decoder;
>> extern AVCodec ff_mwsc_decoder;
>> extern AVCodec ff_mxpeg_decoder;
>> extern AVCodec ff_nuv_decoder;
>> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
>> index 813a43b72e..1cbc9c9ef1 100644
>> --- a/libavcodec/avcodec.h
>> +++ b/libavcodec/avcodec.h
>> @@ -458,6 +458,7 @@ enum AVCodecID {
>> AV_CODEC_ID_LSCR,
>> AV_CODEC_ID_VP4,
>> AV_CODEC_ID_IMM5,
>> + AV_CODEC_ID_MVDV,
>>
>> /* 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 5961af3c85..3e634bbec7 100644
>> --- a/libavcodec/codec_desc.c
>> +++ b/libavcodec/codec_desc.c
>> @@ -1733,6 +1733,13 @@ static const AVCodecDescriptor codec_descriptors[]
>> = {
>> .long_name = NULL_IF_CONFIG_SMALL("Infinity IMM5"),
>> .props = AV_CODEC_PROP_LOSSY,
>> },
>> + {
>> + .id = AV_CODEC_ID_MVDV,
>> + .type = AVMEDIA_TYPE_VIDEO,
>> + .name = "mvdv",
>> + .long_name = NULL_IF_CONFIG_SMALL("MidiVid VQ"),
>> + .props = AV_CODEC_PROP_LOSSY,
>> + },
>>
>> /* various PCM "codecs" */
>> {
>> diff --git a/libavcodec/midivid.c b/libavcodec/midivid.c
>> new file mode 100644
>> index 0000000000..f2d125f2cf
>> --- /dev/null
>> +++ b/libavcodec/midivid.c
>> @@ -0,0 +1,264 @@
>> +/*
>> + * MidiVid decoder
>> + * Copyright (c) 2019 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 "libavutil/imgutils.h"
>> +#include "libavutil/internal.h"
>> +#include "libavutil/intreadwrite.h"
>> +#include "libavutil/mem.h"
>> +
>> +#define BITSTREAM_READER_LE
>> +#include "avcodec.h"
>> +#include "get_bits.h"
>> +#include "bytestream.h"
>> +#include "internal.h"
>> +
>> +typedef struct MidiVidContext {
>> + GetByteContext gb;
>> +
>> + uint8_t uncompressed[524288];
>> + uint8_t *skip;
>> +
>> + AVFrame *frame;
>> +} MidiVidContext;
>> +
>> +static int decode_mvdv(MidiVidContext *s, AVCodecContext *avctx, AVFrame
>> *frame)
>> +{
>> + GetByteContext *gb = &s->gb;
>> + GetBitContext mask;
>> + GetByteContext idx9;
>> + uint16_t nb_vectors, intra_flag;
>> + const uint8_t *vec;
>> + const uint8_t *mask_start;
>> + uint8_t *skip;
>> + int mask_size;
>> + int idx9bits = 0;
>> + int idx9val = 0;
>> + int num_blocks;
>> +
>> + nb_vectors = bytestream2_get_le16(gb);
>> + intra_flag = bytestream2_get_le16(gb);
>> + if (intra_flag) {
>> + num_blocks = (avctx->width / 2) * (avctx->height / 2);
>> + } else {
>> + int skip_linesize;
>> +
>> + num_blocks = bytestream2_get_le32(gb);
>> + skip_linesize = avctx->width >> 1;
>> + mask_start = gb->buffer_start + bytestream2_tell(gb);
>> + mask_size = (avctx->width >> 5) * (avctx->height >> 2);
>> + init_get_bits8(&mask, mask_start, mask_size);
>> + bytestream2_skip(gb, mask_size);
>> + skip = s->skip;
>> +
>> + for (int y = 0; y < avctx->height >> 2; y++) {
>> + for (int x = 0; x < avctx->width >> 2; x++) {
>> + int flag = !get_bits1(&mask);
>> +
>> + skip[(y*2) *skip_linesize + x*2 ] = flag;
>> + skip[(y*2) *skip_linesize + x*2+1] = flag;
>> + skip[(y*2+1)*skip_linesize + x*2 ] = flag;
>> + skip[(y*2+1)*skip_linesize + x*2+1] = flag;
>> + }
>> + }
>> + }
>> +
>> + vec = gb->buffer_start + bytestream2_tell(gb);
>> + if (bytestream2_get_bytes_left(gb) < nb_vectors * 12)
>> + return AVERROR_INVALIDDATA;
>> + bytestream2_skip(gb, nb_vectors * 12);
>> + if (nb_vectors > 256) {
>> + if (bytestream2_get_bytes_left(gb) < (num_blocks + 7) / 8)
>> + return AVERROR_INVALIDDATA;
>> + bytestream2_init(&idx9, gb->buffer_start + bytestream2_tell(gb),
>> (num_blocks + 7) / 8);
>> + bytestream2_skip(gb, (num_blocks + 7) / 8);
>> + }
>> +
>> + skip = s->skip;
>> +
>> + for (int y = avctx->height - 2; y >= 0; y -= 2) {
>> + uint8_t *dsty = frame->data[0] + y * frame->linesize[0];
>> + uint8_t *dstu = frame->data[1] + y * frame->linesize[1];
>> + uint8_t *dstv = frame->data[2] + y * frame->linesize[2];
>> +
>> + for (int x = 0; x < avctx->width; x += 2) {
>> + int idx;
>> +
>> + if (!intra_flag && *skip++)
>> + continue;
>> + if (bytestream2_get_bytes_left(gb) <= 0)
>> + return AVERROR_INVALIDDATA;
>> + if (nb_vectors <= 256) {
>> + idx = bytestream2_get_byte(gb);
>> + } else {
>> + if (idx9bits == 0) {
>> + idx9val = bytestream2_get_byte(&idx9);
>> + idx9bits = 8;
>> + }
>> + idx9bits--;
>> + idx = bytestream2_get_byte(gb) | (((idx9val >> (7 -
>> idx9bits)) & 1) << 8);
>> + }
>> +
>> + dsty[x +frame->linesize[0]] = vec[idx * 12 + 0];
>> + dsty[x+1+frame->linesize[0]] = vec[idx * 12 + 3];
>> + dsty[x] = vec[idx * 12 + 6];
>> + dsty[x+1] = vec[idx * 12 + 9];
>> +
>> + dstu[x +frame->linesize[1]] = vec[idx * 12 + 1];
>> + dstu[x+1+frame->linesize[1]] = vec[idx * 12 + 4];
>> + dstu[x] = vec[idx * 12 + 7];
>> + dstu[x+1] = vec[idx * 12 +10];
>> +
>> + dstv[x +frame->linesize[2]] = vec[idx * 12 + 2];
>> + dstv[x+1+frame->linesize[2]] = vec[idx * 12 + 5];
>> + dstv[x] = vec[idx * 12 + 8];
>> + dstv[x+1] = vec[idx * 12 +11];
>> + }
>> + }
>> +
>> + return intra_flag;
>> +}
>> +
>> +static int lzss_uncompress(MidiVidContext *s, GetByteContext *gb, uint8_t
>> *dst, int size)
>> +{
>> + uint8_t *dst_start = dst;
>> + uint8_t *dst_end = dst + size;
>> +
>> + for (;bytestream2_get_bytes_left(gb) > 0;) {
>> + int op = bytestream2_get_le16(gb);
>> +
>> + for (int i = 0; i < 16; i++) {
>> + if (op & 1) {
>> + int s0 = bytestream2_get_byte(gb);
>> + int s1 = bytestream2_get_byte(gb);
>> + int offset = ((s0 & 0xF0) << 4) | s1;
>> + int length = (s0 & 0xF) + 3;
>> +
>> + if (dst + length >= dst_end ||
>> + dst - offset < dst_start)
>> + return AVERROR_INVALIDDATA;
>> + for (int j = 0; j < length; j++) {
>> + dst[j] = dst[j - offset];
>> + }
>> + dst += length;
>> + } else {
>> + if (dst >= dst_end)
>> + return AVERROR_INVALIDDATA;
>> + *dst++ = bytestream2_get_byte(gb);
>> + }
>> + op >>= 1;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int decode_frame(AVCodecContext *avctx, void *data,
>> + int *got_frame, AVPacket *avpkt)
>> +{
>> + MidiVidContext *s = avctx->priv_data;
>> + GetByteContext *gb = &s->gb;
>> + AVFrame *frame = s->frame;
>> + int ret, key, uncompressed;
>> +
>> + if (avpkt->size <= 12)
>> + return AVERROR_INVALIDDATA;
>> +
>> + bytestream2_init(gb, avpkt->data, avpkt->size);
>> + bytestream2_skip(gb, 8);
>> + uncompressed = bytestream2_get_le32(gb);
>
> The field is 32 bits long, but the buffer you have allocated on heap is
> only 524288 bytes big, so better use av_fast_mallocz instead. It will
> also reduce the amount of allocated memory for most use cases with no
> performance hit.
Nowhere in bitstream is size of uncompressed data after
lzss_uncompress function stored.
And size of uncompressed output can be pretty high with random data,
so this approach works with all samples I have.
>
>> +
>> + if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
>> + return ret;
>> +
>> + if (uncompressed) {
>> + ret = decode_mvdv(s, avctx, frame);
>> + } else {
>> + ret = lzss_uncompress(s, gb, s->uncompressed,
>> sizeof(s->uncompressed));
>> + if (ret < 0)
>> + return ret;
>> + bytestream2_init(gb, s->uncompressed, sizeof(s->uncompressed));
>> + ret = decode_mvdv(s, avctx, frame);
>> + }
>> +
>> + if (ret < 0)
>> + return ret;
>> + key = ret;
>> +
>> + if ((ret = av_frame_ref(data, s->frame)) < 0)
>> + return ret;
>> +
>> + frame->pict_type = key ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
>> + frame->key_frame = key;
>> + *got_frame = 1;
>> +
>> + return avpkt->size;
>> +}
>> +
>> +static av_cold int decode_init(AVCodecContext *avctx)
>> +{
>> + MidiVidContext *s = avctx->priv_data;
>> +
>> + avctx->pix_fmt = AV_PIX_FMT_YUV444P;
>> +
>> + s->frame = av_frame_alloc();
>> + if (!s->frame)
>> + return AVERROR(ENOMEM);
>> + s->skip = av_calloc(avctx->width >> 1, avctx->height >> 1);
>> + if (!s->skip)
>> + return AVERROR(ENOMEM);
>> +
>> + return 0;
>> +}
>> +
>> +static void decode_flush(AVCodecContext *avctx)
>> +{
>> + MidiVidContext *s = avctx->priv_data;
>> +
>> + av_frame_unref(s->frame);
>> +}
>> +
>> +static av_cold int decode_close(AVCodecContext *avctx)
>> +{
>> + MidiVidContext *s = avctx->priv_data;
>> +
>> + av_frame_free(&s->frame);
>> + av_freep(&s->skip);
>> +
>> + return 0;
>> +}
>> +
>> +AVCodec ff_mvdv_decoder = {
>> + .name = "mvdv",
>> + .long_name = NULL_IF_CONFIG_SMALL("MidiVid VQ"),
>> + .type = AVMEDIA_TYPE_VIDEO,
>> + .id = AV_CODEC_ID_MVDV,
>> + .priv_data_size = sizeof(MidiVidContext),
>> + .init = decode_init,
>> + .decode = decode_frame,
>> + .flush = decode_flush,
>> + .close = decode_close,
>> + .capabilities = AV_CODEC_CAP_DR1,
>> + .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
>> +};
>> diff --git a/libavformat/riff.c b/libavformat/riff.c
>> index 048a79e394..25ccedc8ce 100644
>> --- a/libavformat/riff.c
>> +++ b/libavformat/riff.c
>> @@ -489,6 +489,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
>> { AV_CODEC_ID_AGM, MKTAG('A', 'G', 'M', '7') },
>> { AV_CODEC_ID_LSCR, MKTAG('L', 'S', 'C', 'R') },
>> { AV_CODEC_ID_IMM5, MKTAG('I', 'M', 'M', '5') },
>> + { AV_CODEC_ID_MVDV, MKTAG('M', 'V', 'D', 'V') },
>> { AV_CODEC_ID_NONE, 0 }
>> };
>>
>>
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
More information about the ffmpeg-devel
mailing list