[FFmpeg-devel] [PATCH] avcodec: add mvdv video decoder
Paul B Mahol
onemda at gmail.com
Sun Nov 24 12:14:55 EET 2019
On 11/24/19, Paul B Mahol <onemda at gmail.com> wrote:
> 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.
OK, best possible decompression ratio seems to be 16, so I just
allocate 16 * pkt_size.
Works fine.
>
>>
>>> +
>>> + 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