static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame_ptr, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    const uint8_t *buf_end = buf + buf_size;
    DPCMContext *s = avctx->priv_data;
    int out = 0, ret;
    int predictor[2];
    int ch = 0;
     int stereo = s->channels - 1;
     int16_t *output_samples;
 
    if (stereo && (buf_size & 1)) {
        buf_size--;
        buf_end--;
    }

     /* calculate output size */
     switch(avctx->codec->id) {
     case CODEC_ID_ROQ_DPCM:
    case CODEC_ID_XAN_DPCM:
        out = buf_size - 2 * s->channels;
        break;
    case CODEC_ID_SOL_DPCM:
        if (avctx->codec_tag != 3)
            out = buf_size * 2;
        else
            out = buf_size;
        break;
    }
    if (out <= 0) {
        av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
        return AVERROR(EINVAL);
    }

    /* get output buffer */
    s->frame.nb_samples = out / s->channels;
    if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return ret;
    }
    output_samples = (int16_t *)s->frame.data[0];

    switch(avctx->codec->id) {

    case CODEC_ID_ROQ_DPCM:
        buf += 6;

        if (stereo) {
            predictor[1] = (int16_t)(bytestream_get_byte(&buf) << 8);
            predictor[0] = (int16_t)(bytestream_get_byte(&buf) << 8);
        } else {
            predictor[0] = (int16_t)bytestream_get_le16(&buf);
        }

        /* decode the samples */
        while (buf < buf_end) {
            predictor[ch] += s->roq_square_array[*buf++];
            predictor[ch]  = av_clip_int16(predictor[ch]);
            *output_samples++ = predictor[ch];

            /* toggle channel */
            ch ^= stereo;
        }
        break;

    case CODEC_ID_INTERPLAY_DPCM:
        buf += 6;  /* skip over the stream mask and stream length */

        for (ch = 0; ch < s->channels; ch++) {
            predictor[ch] = (int16_t)bytestream_get_le16(&buf);
            *output_samples++ = predictor[ch];
        }

        ch = 0;
        while (buf < buf_end) {
            predictor[ch] += interplay_delta_table[*buf++];
            predictor[ch]  = av_clip_int16(predictor[ch]);
            *output_samples++ = predictor[ch];

            /* toggle channel */
            ch ^= stereo;
        }
        break;

    case CODEC_ID_XAN_DPCM:
    {
        int shift[2] = { 4, 4 };

        for (ch = 0; ch < s->channels; ch++)
            predictor[ch] = (int16_t)bytestream_get_le16(&buf);

        ch = 0;
        while (buf < buf_end) {
            uint8_t n = *buf++;
            int16_t diff = (n & 0xFC) << 8;
            if ((n & 0x03) == 3)
                shift[ch]++;
            else
                shift[ch] -= (2 * (n & 3));
            /* saturate the shifter to a lower limit of 0 */
            if (shift[ch] < 0)
                shift[ch] = 0;

            diff >>= shift[ch];
            predictor[ch] += diff;

            predictor[ch] = av_clip_int16(predictor[ch]);
            *output_samples++ = predictor[ch];

            /* toggle channel */
            ch ^= stereo;
        }
        break;
    }
    case CODEC_ID_SOL_DPCM:
        if (avctx->codec_tag != 3) {
            uint8_t *output_samples_u8 = s->frame.data[0];
            while (buf < buf_end) {
                uint8_t n = *buf++;

                s->sample[0] += s->sol_table[n >> 4];
                s->sample[0]  = av_clip_uint8(s->sample[0]);
                *output_samples_u8++ = s->sample[0];

                s->sample[stereo] += s->sol_table[n & 0x0F];
                s->sample[stereo]  = av_clip_uint8(s->sample[stereo]);
                *output_samples_u8++ = s->sample[stereo];
            }
        } else {
            while (buf < buf_end) {
                uint8_t n = *buf++;
                if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
                else          s->sample[ch] += sol_table_16[n & 0x7F];
                s->sample[ch] = av_clip_int16(s->sample[ch]);
                *output_samples++ = s->sample[ch];
                /* toggle channel */
                ch ^= stereo;
            }
        }
        break;
    }

    *got_frame_ptr   = 1;
    *(AVFrame *)data = s->frame;

    return buf_size;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.