From 50645e50448bed39172af90d92bde92ee84a6055 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Mon, 8 Mar 2021 14:12:06 +0100 Subject: [PATCH] avcodec/ylc: Use only one temporary buffer The effective lifetime of the buffer used to build the VLCs and the buffer containing the bitstream is disjoint, so that one can use a common buffer for both. Reviewed-by: Paul B Mahol Signed-off-by: Andreas Rheinhardt --- libavcodec/ylc.c | 44 ++++++++++++++++++-------------------------- 1 file changed, 18 insertions(+), 26 deletions(-) diff --git a/libavcodec/ylc.c b/libavcodec/ylc.c index a200d04acd..6dc3e60fec 100644 --- a/libavcodec/ylc.c +++ b/libavcodec/ylc.c @@ -39,10 +39,8 @@ typedef struct YLCContext { VLC vlc[4]; uint32_t table[1024]; - uint8_t *table_bits; - uint8_t *bitstream_bits; - int table_bits_size; - int bitstream_bits_size; + uint8_t *buffer; + int buffer_size; BswapDSPContext bdsp; } YLCContext; @@ -312,17 +310,18 @@ static int decode_frame(AVCodecContext *avctx, if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0) return ret; - av_fast_malloc(&s->table_bits, &s->table_bits_size, - boffset - toffset + AV_INPUT_BUFFER_PADDING_SIZE); - if (!s->table_bits) + av_fast_malloc(&s->buffer, &s->buffer_size, + FFMAX(boffset - toffset, avpkt->size - boffset) + + AV_INPUT_BUFFER_PADDING_SIZE); + if (!s->buffer) return AVERROR(ENOMEM); - memcpy(s->table_bits, avpkt->data + toffset, boffset - toffset); - memset(s->table_bits + boffset - toffset, 0, AV_INPUT_BUFFER_PADDING_SIZE); - s->bdsp.bswap_buf((uint32_t *) s->table_bits, - (uint32_t *) s->table_bits, + memcpy(s->buffer, avpkt->data + toffset, boffset - toffset); + memset(s->buffer + boffset - toffset, 0, AV_INPUT_BUFFER_PADDING_SIZE); + s->bdsp.bswap_buf((uint32_t *) s->buffer, + (uint32_t *) s->buffer, (boffset - toffset + 3) >> 2); - if ((ret = init_get_bits8(&gb, s->table_bits, boffset - toffset)) < 0) + if ((ret = init_get_bits8(&gb, s->buffer, boffset - toffset)) < 0) return ret; for (x = 0; x < 1024; x++) { @@ -345,17 +344,12 @@ static int decode_frame(AVCodecContext *avctx, if (ret < 0) return ret; - av_fast_malloc(&s->bitstream_bits, &s->bitstream_bits_size, - avpkt->size - boffset + AV_INPUT_BUFFER_PADDING_SIZE); - if (!s->bitstream_bits) - return AVERROR(ENOMEM); - - memcpy(s->bitstream_bits, avpkt->data + boffset, avpkt->size - boffset); - memset(s->bitstream_bits + avpkt->size - boffset, 0, AV_INPUT_BUFFER_PADDING_SIZE); - s->bdsp.bswap_buf((uint32_t *) s->bitstream_bits, - (uint32_t *) s->bitstream_bits, + memcpy(s->buffer, avpkt->data + boffset, avpkt->size - boffset); + memset(s->buffer + avpkt->size - boffset, 0, AV_INPUT_BUFFER_PADDING_SIZE); + s->bdsp.bswap_buf((uint32_t *) s->buffer, + (uint32_t *) s->buffer, (avpkt->size - boffset) >> 2); - if ((ret = init_get_bits8(&gb, s->bitstream_bits, avpkt->size - boffset)) < 0) + if ((ret = init_get_bits8(&gb, s->buffer, avpkt->size - boffset)) < 0) return ret; dst = p->data[0]; @@ -461,10 +455,8 @@ static av_cold int decode_end(AVCodecContext *avctx) ff_free_vlc(&s->vlc[1]); ff_free_vlc(&s->vlc[2]); ff_free_vlc(&s->vlc[3]); - av_freep(&s->table_bits); - s->table_bits_size = 0; - av_freep(&s->bitstream_bits); - s->bitstream_bits_size = 0; + av_freep(&s->buffer); + s->buffer_size = 0; return 0; }