[FFmpeg-devel] [PATCH] avcodec/agm: add support for higher compression

Nicolas George george at nsup.org
Mon Apr 8 18:32:54 EEST 2019


Paul B Mahol (12019-04-08):
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  libavcodec/agm.c   | 403 +++++++++++++++++++++++++++++++++++++++++++--
>  libavformat/riff.c |   4 +
>  2 files changed, 392 insertions(+), 15 deletions(-)
> 
> diff --git a/libavcodec/agm.c b/libavcodec/agm.c
> index cbd45e8095..e183b7f508 100644
> --- a/libavcodec/agm.c
> +++ b/libavcodec/agm.c
> @@ -71,9 +71,14 @@ typedef struct AGMContext {
>      unsigned flags;
>      unsigned fflags;
>  
> +    uint8_t *output;
> +    int      output_size;
> +
>      MotionVector *mvectors;
>      int           mvectors_size;
>  
> +    VLC vlc;
> +
>      AVFrame *prev_frame;
>  
>      int luma_quant_matrix[64];
> @@ -81,6 +86,13 @@ typedef struct AGMContext {
>  
>      ScanTable scantable;
>      DECLARE_ALIGNED(32, int16_t, block)[64];
> +
> +    int16_t *wblocks;
> +    int      wblocks_size;
> +
> +    int  *map;
> +    int   map_size;
> +
>      IDCTDSPContext idsp;
>  } AGMContext;
>  
> @@ -173,7 +185,84 @@ static int read_code(GetBitContext *gb, int *oskip, int *level, int *map, int mo
>      return 0;
>  }
>  
> -static int decode_intra_block(AGMContext *s, GetBitContext *gb, int size,
> +static int decode_intra_blocks(AGMContext *s, GetBitContext *gb,
> +                               const int *quant_matrix, int *skip, int *dc_level)
> +{
> +    const uint8_t *scantable = s->scantable.permutated;
> +    int level, ret, map = 0;
> +
> +    memset(s->wblocks, 0, s->wblocks_size);
> +
> +    for (int i = 0; i < 64; i++) {
> +        int16_t *block = s->wblocks + scantable[i];
> +
> +        for (int j = 0; j < s->blocks_w;) {
> +            if (*skip > 0) {
> +                int rskip;
> +
> +                rskip = FFMIN(*skip, s->blocks_w - j);
> +                j += rskip;
> +                if (i == 0) {
> +                    for (int k = 0; k < rskip; k++)
> +                        block[64 * k] = *dc_level * quant_matrix[0];
> +                }
> +                block += rskip * 64;
> +                *skip -= rskip;
> +            } else {
> +                ret = read_code(gb, skip, &level, &map, s->flags & 1);
> +                if (ret < 0)
> +                    return ret;
> +
> +                if (i == 0)
> +                    *dc_level += level;
> +
> +                block[0] = (i == 0 ? *dc_level : level) * quant_matrix[i];
> +                block += 64;
> +                j++;
> +            }
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +static int decode_inter_blocks(AGMContext *s, GetBitContext *gb,
> +                               const int *quant_matrix, int *skip,
> +                               int *map)
> +{
> +    const uint8_t *scantable = s->scantable.permutated;
> +    int level, ret;
> +
> +    memset(s->wblocks, 0, s->wblocks_size);
> +    memset(s->map, 0, s->map_size);
> +
> +    for (int i = 0; i < 64; i++) {
> +        int16_t *block = s->wblocks + scantable[i];
> +
> +        for (int j = 0; j < s->blocks_w;) {
> +            if (*skip > 0) {
> +                int rskip;
> +
> +                rskip = FFMIN(*skip, s->blocks_w - j);
> +                j += rskip;
> +                block += rskip * 64;
> +                *skip -= rskip;
> +            } else {
> +                ret = read_code(gb, skip, &level, &map[j], s->flags & 1);
> +                if (ret < 0)
> +                    return ret;
> +
> +                block[0] = level * quant_matrix[i];
> +                block += 64;
> +                j++;
> +            }
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +static int decode_intra_block(AGMContext *s, GetBitContext *gb,
>                                const int *quant_matrix, int *skip, int *dc_level)
>  {
>      const uint8_t *scantable = s->scantable.permutated;
> @@ -218,18 +307,38 @@ static int decode_intra_plane(AGMContext *s, GetBitContext *gb, int size,
>                                int plane)
>  {
>      int ret, skip = 0, dc_level = 0;
> +    const int offset = s->plus ? 0 : 1024;
>  
>      if ((ret = init_get_bits8(gb, s->gbyte.buffer, size)) < 0)
>          return ret;
>  
> -    for (int y = 0; y < s->blocks_h; y++) {
> -        for (int x = 0; x < s->blocks_w; x++) {
> -            ret = decode_intra_block(s, gb, size, quant_matrix, &skip, &dc_level);
> +    if (s->flags & 1) {
> +        av_fast_padded_malloc(&s->wblocks, &s->wblocks_size,
> +                              64 * s->blocks_w * sizeof(*s->wblocks));
> +        if (!s->wblocks)
> +            return AVERROR(ENOMEM);
> +
> +        for (int y = 0; y < s->blocks_h; y++) {
> +            ret = decode_intra_blocks(s, gb, quant_matrix, &skip, &dc_level);
>              if (ret < 0)
>                  return ret;
>  
> -            s->idsp.idct_put(frame->data[plane] + (s->blocks_h - 1 - y) * 8 * frame->linesize[plane] + x * 8,
> -                             frame->linesize[plane], s->block);
> +            for (int x = 0; x < s->blocks_w; x++) {
> +                s->wblocks[64 * x] += offset;
> +                s->idsp.idct_put(frame->data[plane] + (s->blocks_h - 1 - y) * 8 * frame->linesize[plane] + x * 8,
> +                                 frame->linesize[plane], s->wblocks + 64 * x);
> +            }
> +        }
> +    } else {
> +        for (int y = 0; y < s->blocks_h; y++) {
> +            for (int x = 0; x < s->blocks_w; x++) {
> +                ret = decode_intra_block(s, gb, quant_matrix, &skip, &dc_level);
> +                if (ret < 0)
> +                    return ret;
> +
> +                s->idsp.idct_put(frame->data[plane] + (s->blocks_h - 1 - y) * 8 * frame->linesize[plane] + x * 8,
> +                                 frame->linesize[plane], s->block);
> +            }
>          }
>      }
>  
> @@ -242,7 +351,7 @@ static int decode_intra_plane(AGMContext *s, GetBitContext *gb, int size,
>      return 0;
>  }
>  
> -static int decode_inter_block(AGMContext *s, GetBitContext *gb, int size,
> +static int decode_inter_block(AGMContext *s, GetBitContext *gb,
>                                const int *quant_matrix, int *skip,
>                                int *map)
>  {
> @@ -281,7 +390,54 @@ static int decode_inter_plane(AGMContext *s, GetBitContext *gb, int size,
>      if ((ret = init_get_bits8(gb, s->gbyte.buffer, size)) < 0)
>          return ret;
>  
> -    if (s->flags & 2) {
> +    if (s->flags == 3) {
> +        av_fast_padded_malloc(&s->wblocks, &s->wblocks_size,
> +                              64 * s->blocks_w * sizeof(*s->wblocks));
> +        if (!s->wblocks)
> +            return AVERROR(ENOMEM);
> +
> +        av_fast_padded_malloc(&s->map, &s->map_size,
> +                              s->blocks_w * sizeof(*s->map));
> +        if (!s->map)
> +            return AVERROR(ENOMEM);
> +
> +        for (int y = 0; y < s->blocks_h; y++) {
> +            ret = decode_inter_blocks(s, gb, quant_matrix, &skip, s->map);
> +            if (ret < 0)
> +                return ret;
> +
> +            for (int x = 0; x < s->blocks_w; x++) {
> +                int shift = plane == 0;
> +                int mvpos = (y >> shift) * (s->blocks_w >> shift) + (x >> shift);
> +                int orig_mv_x = s->mvectors[mvpos].x;
> +                int mv_x = s->mvectors[mvpos].x / (1 + !shift);
> +                int mv_y = s->mvectors[mvpos].y / (1 + !shift);
> +                int h = s->avctx->coded_height >> !shift;
> +                int w = s->avctx->coded_width  >> !shift;
> +                int map = s->map[x];
> +
> +                if (orig_mv_x >= -32) {
> +                    if (y * 8 + mv_y < 0 || y * 8 + mv_y >= h ||
> +                        x * 8 + mv_x < 0 || x * 8 + mv_x >= w)
> +                        return AVERROR_INVALIDDATA;
> +
> +                    copy_block8(frame->data[plane] + (s->blocks_h - 1 - y) * 8 * frame->linesize[plane] + x * 8,
> +                                prev->data[plane] + ((s->blocks_h - 1 - y) * 8 - mv_y) * prev->linesize[plane] + (x * 8 + mv_x),
> +                                frame->linesize[plane], prev->linesize[plane], 8);
> +                    if (map) {
> +                        s->idsp.idct(s->wblocks + x * 64);
> +                        for (int i = 0; i < 64; i++)
> +                            s->wblocks[i + x * 64] = (s->wblocks[i + x * 64] + 1) & 0xFFFC;
> +                        s->idsp.add_pixels_clamped(&s->wblocks[x*64], frame->data[plane] + (s->blocks_h - 1 - y) * 8 * frame->linesize[plane] + x * 8,
> +                                                   frame->linesize[plane]);
> +                    }
> +                } else if (map) {
> +                    s->idsp.idct_put(frame->data[plane] + (s->blocks_h - 1 - y) * 8 * frame->linesize[plane] + x * 8,
> +                                     frame->linesize[plane], s->wblocks + x * 64);
> +                }
> +            }
> +        }
> +    } else if (s->flags & 2) {
>          for (int y = 0; y < s->blocks_h; y++) {
>              for (int x = 0; x < s->blocks_w; x++) {
>                  int shift = plane == 0;
> @@ -293,7 +449,7 @@ static int decode_inter_plane(AGMContext *s, GetBitContext *gb, int size,
>                  int w = s->avctx->coded_width  >> !shift;
>                  int map = 0;
>  
> -                ret = decode_inter_block(s, gb, size, quant_matrix, &skip, &map);
> +                ret = decode_inter_block(s, gb, quant_matrix, &skip, &map);
>                  if (ret < 0)
>                      return ret;
>  
> @@ -318,12 +474,35 @@ static int decode_inter_plane(AGMContext *s, GetBitContext *gb, int size,
>                  }
>              }
>          }
> +    } else if (s->flags & 1) {
> +        av_fast_padded_malloc(&s->wblocks, &s->wblocks_size,
> +                              64 * s->blocks_w * sizeof(*s->wblocks));
> +        if (!s->wblocks)
> +            return AVERROR(ENOMEM);
> +
> +        av_fast_padded_malloc(&s->map, &s->map_size,
> +                              s->blocks_w * sizeof(*s->map));
> +        if (!s->map)
> +            return AVERROR(ENOMEM);
> +
> +        for (int y = 0; y < s->blocks_h; y++) {
> +            ret = decode_inter_blocks(s, gb, quant_matrix, &skip, s->map);
> +            if (ret < 0)
> +                return ret;
> +
> +            for (int x = 0; x < s->blocks_w; x++) {
> +                if (!s->map[x])
> +                    continue;
> +                s->idsp.idct_add(frame->data[plane] + (s->blocks_h - 1 - y) * 8 * frame->linesize[plane] + x * 8,
> +                                 frame->linesize[plane], s->wblocks + 64 * x);
> +            }
> +        }
>      } else {
>          for (int y = 0; y < s->blocks_h; y++) {
>              for (int x = 0; x < s->blocks_w; x++) {
>                  int map = 0;
>  
> -                ret = decode_inter_block(s, gb, size, quant_matrix, &skip, &map);
> +                ret = decode_inter_block(s, gb, quant_matrix, &skip, &map);
>                  if (ret < 0)
>                      return ret;
>  
> @@ -501,6 +680,180 @@ static int decode_inter(AVCodecContext *avctx, GetBitContext *gb,
>      return 0;
>  }
>  
> +typedef struct Node {
> +    int parent;
> +    int child[2];
> +} Node;
> +
> +static void get_tree_codes(uint32_t *codes, Node *nodes, int idx, uint32_t pfx, int bitpos)
> +{
> +    if (idx < 256 && idx >= 0) {
> +        codes[idx] = pfx;
> +    } else {
> +        get_tree_codes(codes, nodes, nodes[idx].child[0], pfx + (0 << bitpos), bitpos + 1);
> +        get_tree_codes(codes, nodes, nodes[idx].child[1], pfx + (1 << bitpos), bitpos + 1);
> +    }
> +}
> +
> +static void make_new_tree(const uint8_t *bitlens, uint32_t *codes)
> +{
> +    int zlcount = 0, curlen, idx, nindex, last, llast;
> +    int blcounts[32] = { 0 };
> +    int syms[8192];
> +    Node nodes[512];
> +    int node_idx[1024];
> +    int old_idx[512];
> +
> +    for (int i = 0; i < 256; i++) {
> +        int bitlen = bitlens[i];
> +        int blcount = blcounts[bitlen];
> +
> +        zlcount += bitlen < 1;
> +        syms[(bitlen << 8) + blcount] = i;
> +        blcounts[bitlen]++;
> +    }
> +
> +    for (int i = 0; i < 512; i++) {
> +        nodes[i].child[0] = -1;
> +        nodes[i].child[1] = -1;
> +    }
> +
> +    for (int i = 0; i < 256; i++) {
> +        node_idx[i] = 257 + i;;
> +    }
> +
> +    curlen = 1;
> +    node_idx[512] = 256;
> +    last = 255;
> +    nindex = 1;
> +
> +    for (curlen = 1; curlen < 32; curlen++) {
> +        if (blcounts[curlen] > 0) {
> +            int max_zlcount = zlcount + blcounts[curlen];
> +
> +            for (int i = 0; zlcount < 256 && zlcount < max_zlcount; zlcount++, i++) {
> +                int p = node_idx[nindex - 1 + 512];
> +                int ch = syms[256 * curlen + i];
> +
> +                if (nodes[p].child[0] == -1) {
> +                    nodes[p].child[0] = ch;
> +                } else {
> +                    nodes[p].child[1] = ch;
> +                    nindex--;
> +                }
> +                nodes[ch].parent = p;
> +            }
> +        }
> +        llast = last - 1;
> +        idx = 0;
> +        while (nindex > 0) {
> +            int p, ch;
> +
> +            last = llast - idx;
> +            p = node_idx[nindex - 1 + 512];
> +            ch = node_idx[last];
> +            if (nodes[p].child[0] == -1) {
> +                nodes[p].child[0] = ch;
> +            } else {
> +                nodes[p].child[1] = ch;
> +                nindex--;
> +            }
> +            old_idx[idx] = ch;
> +            nodes[ch].parent = p;
> +            if (idx == llast)
> +                goto next;
> +            idx++;
> +            if (nindex <= 0) {
> +                for (int i = 0; i < idx; i++)
> +                    node_idx[512 + i] = old_idx[i];
> +            }
> +        }
> +        nindex = idx;
> +    }
> +
> +next:
> +
> +    get_tree_codes(codes, nodes, 256, 0, 0);
> +}
> +
> +static int build_huff(const uint8_t *bitlen, VLC *vlc)
> +{
> +    uint32_t new_codes[256];
> +    uint8_t bits[256];
> +    uint8_t symbols[256];
> +    uint32_t codes[256];
> +    int nb_codes = 0;
> +
> +    make_new_tree(bitlen, new_codes);
> +
> +    for (int i = 0; i < 256; i++) {
> +        if (bitlen[i]) {
> +            bits[nb_codes] = bitlen[i];
> +            codes[nb_codes] = new_codes[i];
> +            symbols[nb_codes] = i;
> +            nb_codes++;
> +        }
> +    }
> +
> +    ff_free_vlc(vlc);
> +    return ff_init_vlc_sparse(vlc, 13, nb_codes,
> +                              bits, 1, 1,
> +                              codes, 4, 4,
> +                              symbols, 1, 1,
> +                              INIT_VLC_LE);
> +}
> +
> +static int decode_huffman2(AVCodecContext *avctx, int header, int size)
> +{
> +    AGMContext *s = avctx->priv_data;
> +    GetBitContext *gb = &s->gb;
> +    uint8_t lens[256];
> +    uint32_t output_size;
> +    int ret, x, len;
> +
> +    if ((ret = init_get_bits8(gb, s->gbyte.buffer,
> +                              bytestream2_get_bytes_left(&s->gbyte))) < 0)
> +        return ret;
> +

> +    output_size = get_bits_long(gb, 32);
> +
> +    av_fast_padded_malloc(&s->output, &s->output_size,
> +                          output_size * sizeof(*s->output));

Several chances for overflow here.

> +    if (!s->output)
> +        return AVERROR(ENOMEM);
> +
> +    x = get_bits(gb, 1);
> +    len = 4 + get_bits(gb, 1);
> +    if (x) {
> +        int cb[8] = { 0 };
> +        int count = get_bits(gb, 3) + 1;
> +
> +        for (int i = 0; i < count; i++)
> +            cb[i] = get_bits(gb, len);
> +
> +        for (int i = 0; i < 256; i++) {
> +            int idx = get_bits(gb, 3);
> +            lens[i] = cb[idx];
> +        }
> +    } else {
> +        for (int i = 0; i < 256; i++)
> +            lens[i] = get_bits(gb, len);
> +    }
> +
> +    if ((ret = build_huff(lens, &s->vlc)) < 0)
> +        return ret;
> +
> +    x = 0;
> +    while (get_bits_left(gb) > 0 && x < output_size) {
> +        int val = get_vlc2(gb, s->vlc.table, s->vlc.bits, 3);
> +        if (val < 0)
> +            return AVERROR_INVALIDDATA;
> +        s->output[x++] = val;
> +    }
> +
> +    return 0;
> +}
> +
>  static int decode_frame(AVCodecContext *avctx, void *data,
>                          int *got_frame, AVPacket *avpkt)
>  {
> @@ -509,6 +862,7 @@ static int decode_frame(AVCodecContext *avctx, void *data,
>      GetByteContext *gbyte = &s->gbyte;
>      AVFrame *frame = data;
>      int w, h, width, height, header;
> +    int compressed_size;
>      int ret;
>  
>      if (!avpkt->size)
> @@ -524,13 +878,19 @@ static int decode_frame(AVCodecContext *avctx, void *data,
>      if (avpkt->size < s->bitstream_size + 8)
>          return AVERROR_INVALIDDATA;
>  
> -    s->key_frame = s->fflags & 0x1;
> +    s->key_frame = avpkt->flags & AV_PKT_FLAG_KEY;
>      frame->key_frame = s->key_frame;
>      frame->pict_type = s->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
>  
>      if (header) {
> -        av_log(avctx, AV_LOG_ERROR, "header: %X\n", header);
> -        return AVERROR_PATCHWELCOME;
> +        if (avctx->codec_tag == MKTAG('A', 'G', 'M', '0') ||
> +            avctx->codec_tag == MKTAG('A', 'G', 'M', '1'))
> +            return AVERROR_PATCHWELCOME;
> +        else
> +            ret = decode_huffman2(avctx, header, (avpkt->size - s->bitstream_size) - 8);
> +        if (ret < 0)
> +            return ret;
> +        bytestream2_init(gbyte, s->output, s->output_size);
>      }
>  
>      s->flags = 0;
> @@ -564,9 +924,14 @@ static int decode_frame(AVCodecContext *avctx, void *data,
>  
>      for (int i = 0; i < 3; i++)
>          s->size[i] = bytestream2_get_le32(gbyte);
> +    if (header)
> +        compressed_size = s->output_size;
> +    else
> +        compressed_size = avpkt->size;
>      if (s->size[0] < 0 || s->size[1] < 0 || s->size[2] < 0 ||
> -        32LL + s->size[0] + s->size[1] + s->size[2] > avpkt->size)
> +        32LL + s->size[0] + s->size[1] + s->size[2] > compressed_size) {
>          return AVERROR_INVALIDDATA;
> +    }
>  
>      if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
>          return ret;
> @@ -608,7 +973,8 @@ static av_cold int decode_init(AVCodecContext *avctx)
>  
>      avctx->pix_fmt = AV_PIX_FMT_YUV420P;
>      s->avctx = avctx;
> -    s->plus = avctx->codec_tag == MKTAG('A', 'G', 'M', '3');
> +    s->plus = avctx->codec_tag == MKTAG('A', 'G', 'M', '3') ||
> +              avctx->codec_tag == MKTAG('A', 'G', 'M', '7');
>  
>      avctx->idct_algo = FF_IDCT_SIMPLE;
>      ff_idctdsp_init(&s->idsp, avctx);
> @@ -632,9 +998,16 @@ static av_cold int decode_close(AVCodecContext *avctx)
>  {
>      AGMContext *s = avctx->priv_data;
>  
> +    ff_free_vlc(&s->vlc);
>      av_frame_free(&s->prev_frame);
>      av_freep(&s->mvectors);
>      s->mvectors_size = 0;
> +    av_freep(&s->wblocks);
> +    s->wblocks_size = 0;
> +    av_freep(&s->output);
> +    s->output_size = 0;
> +    av_freep(&s->map);
> +    s->map_size = 0;
>  
>      return 0;
>  }
> diff --git a/libavformat/riff.c b/libavformat/riff.c
> index a8594b0607..3d77efa7d7 100644
> --- a/libavformat/riff.c
> +++ b/libavformat/riff.c
> @@ -477,8 +477,12 @@ const AVCodecTag ff_codec_bmp_tags[] = {
>      { AV_CODEC_ID_RASC,         MKTAG('R', 'A', 'S', 'C') },
>      { AV_CODEC_ID_HYMT,         MKTAG('H', 'Y', 'M', 'T') },
>      { AV_CODEC_ID_ARBC,         MKTAG('A', 'R', 'B', 'C') },
> +    { AV_CODEC_ID_AGM,          MKTAG('A', 'G', 'M', '0') },
> +    { AV_CODEC_ID_AGM,          MKTAG('A', 'G', 'M', '1') },
>      { AV_CODEC_ID_AGM,          MKTAG('A', 'G', 'M', '2') },
>      { AV_CODEC_ID_AGM,          MKTAG('A', 'G', 'M', '3') },
> +    { AV_CODEC_ID_AGM,          MKTAG('A', 'G', 'M', '6') },
> +    { AV_CODEC_ID_AGM,          MKTAG('A', 'G', 'M', '7') },
>      { AV_CODEC_ID_NONE,         0 }
>  };
>  

Regards,

-- 
  Nicolas George
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